This recipe is from Diana Kennedy’s Mexican Cuisines.
“You will find this sauce on Mexican tables at any time of day, for it goes well with breakfast eggs, with roasted or broiled meats at lunchtime, or tacos at evening, and there are people who put a spoonful of it into their frijoles de olla. It is marvelously crunchy and refreshing served just with tortillas. The Sinaloa version calls for some scallions and lime juice in place of the onions and water, and the Yucatecan version, x-ni-pec, substitutes Seville orange juice for the water.
Finely dice fresh ripe tomatoes, onion, and serrano peppers with seeds in equal amounts. Mix well with fresh chopped cilantro, add liquid and salt to taste. Although this can be made up to three hours ahead, it is best made at almost the last minute, for it soon loses its crispness and the coriander its sharp flavor.”
