Preheat oven to 400.
In a blender or food processor add the cheese, cornstarch, sour cream, and beer. Process until smooth, set aside.
Sprinkle the chicken cubes with chili powder, onion powder, garlic powder, cumin, and salt, toss until well coated.
Heat the olive oil in a skillet over medium high heat. Add the onion, cook until softened, about 5 minutes. Stir in the garlic.
Add the chicken, cook until browned on all sides.
Pour in the cheese sauce, simmer until thickened, remove from heat, stir in the tomatoes and green onions.
Cut the stem off the chilies, remove the seeds inside. Spoon the chicken and cheese mixture into the peppers.
Place upright in oven safe coffee mugs, place coffee mugs on a baking sheet.
Bake at 400 for 15-18 minutes or until peppers have softened.