Shred 1 cup Monterey Jack and 1 cup white cheddar cheese. Mince ¼ serrano pepper, ¼ poblano pepper, and ¼ chipotle pepper (rehydrated or canned). Dice ¼ yellow onion and mince 2 garlic cloves.
Heat 1 tbsp oil in a medium saucepan over medium heat. Add the onion and cook for 4-5 minutes until soft. Stir in the peppers and cook for 2-3 minutes. Add garlic, cumin, and coriander, and cook for 30 seconds.
Mix 1 tbsp cornstarch with 2 tbsp cold water in a small bowl to make a slurry.
Lower the heat. Pour in 1 cup heavy cream and stir in the cornstarch slurry. Gradually add shredded cheeses, stirring until melted and smooth.
Stir in ¼ cup diced tomatoes and ¼ cup cultured cream (or sour cream). Taste and season with salt.
Serve warm with tortilla chips, veggies, or tortillas.