Combine the tomatoes, onions, peppers, apples, garlic, vinegar, and salt in a large,nonreactive saucepan and bring to a boil. Reduce the heat and simmer, stirring occasionally, until thickened, about an hour.
Stir in the jalapenos, cilantro, and cumin and simmer for 5 more minutes. Carefully puree the mixture using a stick blender or in a traditional countertop blender (in batches if necessary) until still somewhat chunky.
If canning, return the pureed relish to a boil, then ladle the hot mixture into hot jars, leaving 1/4-inch head space. Process 15 minutes in a boiling-water canner. Store in a cool, dark place.