3 tablespoons vegetable oil
5 cloves garlic, peeled
40 to 50 Serranos or 12 large jalape?s
1/2 medium onion, sliced 1/8 inch thick
1/2 cup fruit vinegar or cider vinegar
2 bay leaves
1 scant teaspoon mixed thyme, marjoram and Mexican oregano
4 peppercorns, coarsely ground
1/2 teaspoon salt

Heat oil in a skillet over medium heat. Add whole garlic cloves and fry, stirring frequently, until they are lightly browned; remove and set aside. Add chiles and onion; fry, stirring frequently, until the onion is translucent, about 5 minutes.

Add 1/2 cup water to the skillet. Add browned garlic, vinegar, bay leaves, herbs, pepper and slat. Cover and simmer over medium-low heat for about 10 minutes until the chiles are olive green.

Remove from the heat; pour into a non-reactive container. Cool and season with additional salt, if necessary. Cover and refrigerate for a day before using.