Prep Cheese: Shred cheese and add to a medium-sized bowl. Sprinkle with cornstarch, mix well, and set aside.
Saute: Add butter to a medium-size pot and melt over medium heat. Add onion and jalapeno and saute for 3-4 minutes. Add cumin, paprika, salt, onion powder, and garlic powder and stir, and saute 1 more minute.
Add Tomatoes and Milk: Add the tomatoes and saute for 1 minute and then slowly add the evaporated milk, stirring as you add.
Add Cheese: Add the cheese and mix well while the cheese melts into a sauce. Taste and add additional salt if desired.
Serve and Enjoy! Top with some fresh cilantro to garnish and diced tomatoes. Serve hot or store in the fridge and reheat before serving, or transfer to a crock pot on "warm" setting.