Cook jumbo shells according to box instructions and drain in colander.
Preheat oven to 350 degrees. Heat olive oil in large skillet over medium heat. Cook onion for 2-3 minutes. Reduce heat to medium low and add garlic. Cook for one minute. Add pork and barbecue sauce. Simmer for 5 minutes. Remove from heat.
Stuff each shell with a heaping tablespoon of pork and place in 13 x 9 inch casserole dish sprayed with nonstick olive oil spray. Sprinkle with the cheeses.
Cook for 25 minutes or until the cheese is melted.