- Toss together Monterey Jack cheese, Cheddar cheese and flour until well coated; set aside.
- Heat oil in cast-iron skillet or heavy-bottom pan set over medium heat; cook onion, jalapeño, garlic, salt, pepper, chili powder and cumin for 3 to 5 minutes or until softened.
- Slowly pour in milk; reduce heat to low. Add cheese mixture, a handful at a time, stirring until completely melted before adding the next handful (do not allow to boil; remove pan from heat if needed).
- Sprinkle tomatoes, pickled peppers and cilantro over dip. Serve with crackers.
Tip: Use pickled jalapeño, serrano, pepperoncini or banana peppers.