Tomatillos are Mexican green tomatoes in husks. Their flavor has a hint of lemon, apple and herbs. Tomatillos are popular in Mexican and Southwest cooking and used in a variety of dishes.
In place of fresh tomatillos, you can use 3 cans (12 oz each) whole tomatillos; drain the liquid. Decrease the salt to 1/2 teaspoon, using 1/4 teaspoon each in the processed mixture and the marinade.