Chop the shrimp into small pieces. In an 8x8 inch baking dish, combine shrimp, yellow onion, bell pepper, garlic, mayonnaise, vegetable oil, Old Bay (TM) seasoning, black pepper, salt, and 3/4 cup of cheese. Mix well, use reserved 1/4 cup cheese to cover the top in an even layer.
Bake at 350 degrees F (175 degrees C) for 25 to 30 minutes.
