To make a simple green tomato salsa, broil and blacken 1 pound of green tomatoes. Core and peel the tomatoes. Puree the tomatoes, 1/2 of a medium white onion, 2 or 3 jalapeño peppers, 1/2 cup of chopped cilantro, and salt to taste. Add water and salt as needed.
To make a mild green tomato salsa, grill and blacken 1 medium onion sliced 1/2 inch thick and 1 pound of green tomatoes. Core and peel the tomatoes, and coarsely chop both the tomatoes and the onion slices. Combine the tomatoes and onion with 2 tablespoons of chopped cilantro, 1 large coarsely chopped tomato, 1 tablespoon of lime juice, and 2 tablespoons of olive oil into a bowl. Season the salsa with salt and pepper to taste.
To prepare canned green tomato salsa, heat 6 half-pint preserving jars in simmering water. Boil 7 cups of cored, peeled, and chopped green tomatoes; 5 to 10 chopped jalapeño or habanero peppers; 2 cups of chopped red onion; 2 finely chopped garlic cloves; and 1/2 cup of lime juice. Add 1/2 cup of chopped cilantro, 2 teaspoons of cumin, 1 teaspoon of oregano, 1 teaspoon of salt and 1 teaspoon of pepper. Allow the mixture to simmer for five minutes. Fill the jars with hot salsa, leaving 1/2 inch at the top. Add the lids and bands to the jars. Boil the jars in a boiling water canner for 20 minutes. Remove jars, and allow them to cool. Ensure the lids do not flex after 24 hours.