Prepare your cheese filling by combining shredded cheese, cream cheese, diced red onion, and diced jalapenos. Reserve 1 cup of the mixture and store in the refridgerator for use in the cheese sauce.
Lay chicken breasts flat on a sheet of parchment or wax paper. Using the palm of your hand, flatten the breasts so that the entire piece of meat is fairly uniform in thickness.
Using a sharp knife, preferably a filet knife, turn the breast on its side and starting about an inch from the edge, cut across the breast to form a pocket. What we are going for is something that looks a bit like a canoe when laying on its side.
Salt and pepper both sides.
Turn the breast back over on its side and stuff with cheese mixture, evenly dividing it between all four pieces of meat.
Place chicken breasts, cheese side up, in a casserole dish or cast iron skillet and cover with aluminum foil, then put them in the oven.
In the meantime, begin preparing your cheese sauce by placing your sliced green onions, garlic, and beer into a small sauce pan. Allow to marinate at room temperature while the meat cooks.
When chicken is cooked through, remove foil and top with diced green peppers, sliced olives, and diced tomatoes. Return to the oven until toppings are tender.
In the meantime, finish preparing your cheese sauce by first removing and disgarding the garlic cloves.
Add the milk and crumbled bacon and bring to a boil over medium heat, stirring constantly.
Reduce heat and add in the reserved cheese mixture, stirring until completely melted.
Top chicken breasts with beer-cheese sauce. I like to serve these over rice!