Tomatillo salsa verde tastes better broiled, not boiled

To make salsa verde with tomatillos, husk and rinse 1 pound of them and broil them with 1 or 2 serranos, a quarter of a white onion and 2 unpeeled garlic cloves, about 6 inches from the element, until blackened in spots and slumped, 10 to 12 minutes total. Blend everything, pan juices included, with a half cup of cilantro and 1 teaspoon of kosher salt. Broiling instead of boiling gives the salsa a deeper flavor and a thicker body.

Don't boil them.

Most recipes tell you to simmer tomatillos until they turn olive drab, then blend. It works, but you get a salsa that's thin, sharply sour and tastes mostly of green acid. The broiler does the opposite. It drives off water, browns the sugars on the skin and softens the sourness.

Why boiled tomatillo salsa tastes thin

A tomatillo is mostly water and acid with a fair amount of pectin. Boiling keeps all that water in the fruit and usually adds some, because recipes ask for a splash of the cooking liquid to get the blender going. Nothing browns in simmering water, so the only flavors you get are the ones the raw fruit already had.

Under a broiler, the skins blister and char in patches, the flesh collapses into its own juice, and that juice reduces slightly on the pan. You get smoke, a little sweetness and a thicker sauce without adding anything. I made two batches from the same 2-pound bag, one boiled for 6 minutes and one broiled, and blended them with identical amounts of chile, onion, garlic, cilantro and salt.

That next-day thickening is the pectin setting as the salsa chills. It's normal, and a spoonful of water loosens it.

From the grower's side at Miniature Harvest, pick tomatillos that fill their husks, sometimes splitting them, and feel firm like an underripe plum. Bright green ones are the tartest. Ones turning yellow are sweeter and softer, which is fine for salsa but means you'll want a squeeze of lime at the end. Store them in their husks in a paper bag in the fridge and they'll hold for a couple of weeks. If you're not sure what's good right now, see what's in season near you.

How to broil and blend it

Quantities are per pound of tomatillos, which is roughly 8 to 10 medium ones and makes about 2 cups of salsa. Scale everything straight up.

1. Husk and rinse. Pull off the papery husks and wash the fruit under warm water, rubbing off the sticky film. That coating tastes bitter if you leave it on.
2. Set the rack. Put an oven rack about 6 inches below the broiler element and line a sheet pan with foil. Turn the broiler to high and let it heat for 5 minutes.
3. Load the pan. Lay out the tomatillos stem side down, the chiles, the onion quarter cut side up, and the garlic still in its skin. The skin keeps the cloves from scorching.
4. Broil the first side. Give it 5 to 6 minutes, until the tops are blackened in patches. Pull the garlic and chiles as soon as they're blistered and soft, which usually happens first.
5. Flip and finish. Turn the tomatillos and onion and broil 4 to 6 minutes more. They're done when they slump and leak juice, not when they hit a time. Squeeze two or three. They should feel like water balloons.
6. Scrape everything in. Peel the garlic, stem the chiles, and tip the tomatillos, onion and every bit of pan juice into a blender. The juice is where a lot of the browned flavor ends up.
7. Pulse, don't puree. Add a half cup of cilantro, stems included, and 1 teaspoon of kosher salt. Pulse 8 to 10 times for a salsa with some texture. Running the blender flat out whips in air and turns it pale and foamy.
8. Taste it cool. Let it sit 15 minutes, then taste on a chip. Cold mutes salt, so adjust at the temperature you'll serve it. Add lime only if it tastes flat rather than sharp.

Heat control is mostly the chile. One serrano per pound gives a medium salsa. For mild, seed it or swap in a jalapeño. If it comes out too sour, a pinch of sugar or a quarter of a ripe avocado pulsed in will round it off. For more on balancing that acid, see how acid works in cooking.

Restaurant kitchens often char tomatillos on a dry comal or plancha, turning them by hand. It's a good method if you already own the pan, but it takes attention and smokes up a home kitchen. The broiler gets you nearly the same char with one flip. A grill works too, in a basket over direct heat.

Related: Cooked vs Raw Tomatoes for Salsa: When Each One Wins

When raw or boiled is the better call

Broiling isn't always the answer. A raw salsa verde, with tomatillos blended uncooked with chile, onion, cilantro and salt, is sharper and brighter, and it suits rich food like carnitas or fried fish. Boiling makes sense when the salsa is going into a braise or chilaquiles, where it will cook again and you want a clean, simple green base.

The method also stops at the fridge. USDA's general guidance for refrigerated leftovers is 3 to 4 days, so treat fresh salsa the same way. It also freezes well for a few months, though it's a little looser once thawed. If you want shelf-stable jars, don't adapt this recipe. Use a tested tomatillo salsa recipe from the National Center for Home Food Preservation, because acidity for safe canning has to be measured, not guessed.

I broil the garlic in its skin, pull the serrano the minute it blisters, and salt again only after the salsa has cooled.