Preheat oven to 350°F.
Heat oil in a saucepan over low heat; add garlic, salt and pepper and cook for 1 minute. Add flour using a whisk, stirring until mixture is smooth and bubbling but not brown. Increase heat to medium and gradually add milk, stirring constantly. Continue to stir and cook until mixture has thickened and has come to a boil for 1 minute.
Remove from heat and gradually stir in cheeses until melted and sauce is smooth. Steam fresh broccoli with a small amount of water in a microwave-safe container for 2 minutes. Drain broccoli and combine with bell peppers, capers, sausage and pasta in a large mixing bowl. Pour cheese sauce over pasta mixture and stir to combine.
Transfer to a greased 13 x 9-inch baking dish; top with bread crumbs. Bake for 30 to 40 minutes or until lightly browned and bubbling around the edges.