This is a raw egg emulsion, so two things matter more than anything else: use pasteurized eggs, and add the oil slowly. Get those right and the rest is straightforward.

The other thing worth knowing before you start: the chile goes in after the emulsion is built, not before. Roasted chile carries water, and water added while you are still emulsifying is the most reliable way to break it.

Makes about 1 1/2 cups. Ten minutes of work, then an hour in the fridge.

Raw eggs, and the safe way to do this

The yolks in this sauce are never cooked. That is how mayonnaise and aioli work, and it is worth being straight about rather than glossing over.

Use pasteurized eggs. They are sold in shell form in most supermarkets, usually marked pasteurized on the carton, and they behave identically in an emulsion. FDA guidance is to use pasteurized eggs in any recipe where the egg stays raw or undercooked.

Anyone who should not eat raw egg should not eat this version. That includes young children, older adults, pregnant women and anyone with a weakened immune system, per FDA and USDA guidance. Make the shortcut version below for them instead, which has no raw egg in it at all.

Keep it cold. Make it, chill it, and keep it in the refrigerator. This is not a sauce to leave out on a table for an afternoon.

None of that is a reason to avoid the recipe. It is a reason to buy the right eggs.

The shortcut version, and when to use it

Stir 1/3 cup of drained roasted green chile, two to four cloves of minced garlic, a teaspoon of lime juice, salt and pepper into a cup and a half of good store bought mayonnaise. Chill an hour.

It takes three minutes, it has no raw egg in it, it keeps to the date on the mayonnaise jar, and it is honestly close. Commercial mayonnaise is a more stable emulsion than anything you will build by hand, so it will not break on you either.

Make the real thing when you want the texture and the olive oil flavor, which is a real difference and the reason the from scratch version exists. Make the shortcut when you are feeding a crowd, when you are short on time, or when someone at the table should not have raw egg. Neither one is the lesser choice.

Building the emulsion

An emulsion is oil suspended in water in droplets small enough to stay there. The yolk is what holds it, because lecithin in the yolk coats each droplet and keeps them from finding each other. Everything about the method serves that.

• Start with the yolks, garlic and lime juice alone. Blend until thick and opaque. That opacity is the emulsion forming. If it stays translucent and thin, stop and fix it before you add oil.
• Room temperature yolks emulsify more easily than cold ones. Twenty minutes on the counter is enough.
• The first quarter cup of oil is the dangerous part. Go in a slow thread, almost drop by drop, with the blender running. Once it has visibly thickened you can speed up.
• Neutral oil first, then the olive oil. That is the order in the recipe and it is deliberate. Building the base on neutral oil gives you a stable emulsion before you introduce a stronger flavored oil, and it keeps the olive oil taste from turning bitter, which it can when whipped hard.
• Fresh lime juice, not bottled. The recipe says so and it is correct. Bottled juice is usually weaker and the acid matters here for both the emulsion and the flavor.
• An immersion blender in a tall narrow cup is the easiest tool. The head sits right in the yolks, which means the oil gets pulled down in a controlled stream rather than sitting on top.

One honest note on the name. Traditional aioli from Provence and Catalonia is garlic pounded into olive oil with no egg at all. Adding yolks makes it, strictly, a garlic mayonnaise. Almost every restaurant in the country calls that aioli, and so do we, but if you have had the real thing and wondered why yours is different, that is why.

Fixing one that broke

A broken emulsion looks thin, greasy and separated, usually because the oil went in too fast. It is recoverable.

Put a fresh egg yolk in a clean bowl. Whisk it, then add the broken mixture into it the same way you added the oil originally, in a very slow thread. You are rebuilding around a new yolk, and the broken sauce becomes the oil. It nearly always works.

If you would rather not use another egg, a teaspoon of cold water whisked into a fresh bowl can sometimes start it, but the yolk method is more reliable.

The chile, and when it goes in

A third of a cup of roasted green chile into a cup and a half of aioli is a real presence. This is a green sauce, not a white one with flecks in it.

Drain it first. Roasted chile carries its own liquid, and here that liquid thins a finished emulsion and can slacken it past the point of being spreadable. A minute in a sieve. If you are using frozen chile, thaw and drain it harder.

It goes in last, after the oil is fully emulsified, with the salt and pepper. Blend just until smooth. Overworking at this stage does nothing good.

Medium chile, two cloves of garlic and this much lime is a balanced sauce. The recipe note suggests Hot for more heat, and it works well here because the oil and yolk buffer heat considerably. Four cloves of garlic makes it properly assertive, which is the version to make if it is going on a burger.

How long it keeps

Refrigerate it, and use it within about four days. Homemade mayonnaise is a raw egg product with no preservatives, and four days is the guidance we would give a customer rather than the outside limit some recipes quote. Keep it in a covered container in the coldest part of the fridge.

Give it an hour before you serve it. The garlic softens and the chile spreads through the sauce. It is noticeably better cold and rested than it is straight out of the blender.

Do not freeze it. The emulsion separates on thawing and does not come back.

Do not leave it out. Back in the fridge between uses, and if it has been on a table for more than a couple of hours, throw it out. The shortcut version made with commercial mayonnaise is much more forgiving on all of these points.

What to put it on

Fries are the obvious one and the reason most people make it. Beyond that it is a good sauce on anything fried or grilled: burgers, chicken sandwiches, fish tacos, roasted potatoes, corn, grilled asparagus. Thinned with a little more lime juice it works as a salad dressing.

It is also the right sauce for green chile shrimp tostadas, and it goes next to rolled tacos in place of sour cream.

The chile is 16 oz jars of flame roasted Hatch green chile, Medium or Hot, four ingredients: Hatch chile, salt, garlic, lime juice. A third of a cup per batch means a jar makes about six. If you go through chile faster than that, frozen in 5 lb bags is the same chile in volume. The substitutions guide covers what to use if you cannot get Hatch chile, and the recipe archive is free.

Common questions

Is homemade aioli safe to eat?

The yolks are raw, so use pasteurized eggs, which most supermarkets sell in the shell. FDA guidance is to use pasteurized eggs in anything where the egg stays raw. People who should avoid raw egg, including young children, older adults, pregnant women and anyone immunocompromised, should have the version made with store bought mayonnaise instead.

How long does homemade green chile aioli last?

About four days, refrigerated and covered. It is a raw egg sauce with no preservatives. The version made with commercial mayonnaise keeps to the date on the jar.

Why did my aioli break?

The oil went in too fast, or the yolk base was not thick before the oil started. Fix it by whisking a fresh yolk in a clean bowl and adding the broken sauce into it very slowly.

Can I make it without raw egg?

Yes. Stir the chile, garlic, lime juice, salt and pepper into a cup and a half of good store bought mayonnaise and chill it for an hour. It takes three minutes and it is close.

When does the green chile go in?

Last, after the oil is fully emulsified. Drain it first. Water added mid emulsion is the most common way to break one.

Is aioli the same as mayonnaise?

Traditional aioli is garlic and olive oil with no egg. This version uses yolks, which strictly makes it a garlic mayonnaise. Nearly everyone calls that aioli now.

Can I freeze it?

No. The emulsion separates when thawed and does not recover.

How spicy is it?

Medium chile in a sauce this rich lands mild. The oil and yolk buffer heat, so Hot chile is a reasonable default if you like heat.

The short version

Pasteurized eggs, room temperature. Blend yolks, garlic and fresh lime until thick and opaque. Add the neutral oil in a thread, then the olive oil. Drained chile, salt and pepper last. An hour in the fridge, four days of life, no freezing. If any of that is inconvenient, the store bought mayonnaise version is three minutes and nearly as good.