Mellow, Colby cheese, no mushrooms, just the way my MIL loves it. I make this casserole ahead for a change of pace for my MIL. This grew out of Johnny Marzetti in Jean Anderson's American Century Cookbook.
Bring a large pot of lightly salted water to a boil. Place the farfalle (aka bow ties) into the pot, cook 8 to 10 minutes, until al dente, and drain.
Preheat oven to 350 degrees Fahrenheit.
Lightly grease 11 x 7 x 2-inch baking dish (or 8x8-inch pan) and set aside.
Heat olive oil in a very large heavy skillet over moderate heat 1 minute.
Add onion and garlic. Stir-fry until limp, about 3 minutes.
Add chopped bell pepper and stir-fry about 5 minutes.
Add beef and cook and stir, breaking up clumps, until no longer red, about 5 minutes.
Drain the beef mixture in a fine mesh colander due to the volume of high water content onions and bell peppers.
Off heat, mix in tomato sauce, and all but 1 cup cheese.
Transfer to baking dish, add bow ties, and toss gently but thoroughly to mix.
Scatter remaining 1 cup cheese on top. (Add grated parmesan cheese if more is needed.).
Bake, uncovered, until browned and bubbling, 35-40 minutes, and serve.
Due to the high moisture content of the onions and bell peppers, this recipe does not freeze as well as other versions of this casserole. If you do freeze it, please reheat in the oven, not the microwave.