Spray a large crockpot with nonstick cooking spray and set the temperature to high.
Add the tomatoes, milk, lime juice, cheeses and cilantro; mix well.
30 ounces fire-roasted diced tomatoes with green chiles, 24 ounces whole fat evaporated milk, 1 whole lime, 1 pound white American block-style cheese, 1 pound yellow American block-style cheese, 1 pound Velveeta Queso Blanco cheese, 7 ounces Supremo Mexican Blend cheese, ½ bunch fresh cilantro
Place the lid on top of the crockpot.
Place the oil, onions, and jalapeno peppers in a medium skillet set over medium heat. Sauté the vegetables until tender and translucent, about 3-4 minutes.
2 tablespoons olive oil, 2 jalapeno peppers, ½ yellow onion
Add cumin, red pepper flakes, and chili powder; stir well and cook for an additional 30 seconds, stirring continuously.
1 teaspoon ground cumin, ¼ teaspoon crushed red pepper flakes, 1 teaspoon chili powder
Add the sautéed vegetables to the cheese mixture in the crockpot and stir well.
Replace the lid, leaving it slightly ajar. Stir the cheese several times until the cheese is completely melted, about 30 minutes.
Lower the temperature to warm and stir about every 15-20 minutes. If needed, add a little evaporated milk if it thickens during warming.
Serve with your favorite chips/vegetables/crackers.