1. Heat 1 T. olive oil in a large high-sided skillet over medium-high heat.
2. Add your base ingredient and cook, breaking up any ground meat with a spoon, until the vegetables are tender or the meat is cooked through. Pour off any excess fat.
3. Pour 2/3 c. half-and-half, then add both cheeses.
4. Add one 10 oz. can mild diced tomatoes with chiles, such as Ro-Tel. (If using all white cheeses, add a 4 oz. can green chiles instead; the canned tomatoes may make your queso pink). Cook the queso over medium heat until the cheese is melted, about 6 minutes; remove from the heat.
5. Transfer the queso to a bowl, if desired, and top with any combination of the following. Serve with chips.

Slow Cooker:

1. Cook your base ingredients as directed, then transfer to a slow cooker and add the remaining ingredients. Cook on high for 50 minutes, stirring halfway through and again at the end.