Heat oil over medium heat in large pan.
Add onions and minced garlic, sauté for 3-5 minutes or until onions are softened.
Add ground beef and red pepper; brown thoroughly. Once meat is cooked completely, drain grease.
In a 9x11-inch baking dish, cover bottom of dish with one layer of frozen raviolis (half the package), then top with ½ jar of tomato sauce. Next, top with cooked ground beef, onions and garlic mixture.
On top of ground beef, make one more layer with remaining raviolis.
Top with remaining tomato sauce.
Top with part-skim mozzarella cheese.
Cover with foil and place in oven. Cook for 30 minutes or until sauce is bubbling on edges.
Remove foil and cook for 5 more minutes to brown cheese.
Remove from oven; let lasagna cool for 5 minutes before serving.