Salsa mexicana cruda, or uncooked Mexican sauce, is a mixture of chopped tomatoes, finely chopped white onion, loosely chopped cilantro (not minced, as it is an aromatic and you wouldn’t want to “bruise” it), minced serrano chilies, salt to taste and a splash of water. It is ever present, in all parts of Mexico, and delicious with almost every Mexican dish from the first egg in the morning, with frijoles de la olla, appetizers, and right through meat dishes served at la comida. It is made in small batches, and served at room temperature (refrigeration steals its thunder) within a couple of hours of conception so it is still crunchy, freshly fragrant and piquant. A guide to the amount of each ingredient might be a generous cup of chopped tomatoes to a half cup each of onions and cilantro, with a couple of chili serranos per cup of tomatoes, and salt to taste. Put a plate of quartered limes nearby.
If you want to peel the tomatoes, just put them in boiling water for a minute or so while you chop the onion, then into an ice water bath and the skin will slip right off after you make the first cut. Don’t let the tomatoes sit in the hot water too long, or they will get mushy. If you want the salsa to be picanté, then mince the serrano chilies, membrane, seeds, and all. If you prefer a milder salsa, then take out the white membrane and seeds before chopping them, and maybe add one more chili. Remember to wear gloves or to hold the raw chili down with a plastic bag while handling them if you wear contact lenses and intend to either put them in or take them out in the next few hours. And as for you gentlemen chefs, well, just use plastic gloves. Buen provecho!