Preheat an oven-safe skillet on the stovetop over medium heat. Add the ground beef to the skillet, breaking apart the larger chunks as it cooks. Season the beef with salt and pepper.
Add in the diced onion and bell peppers, sautéing the mixture until the veggies soften.
Stir in the cream cheese and remove the mixture from the stovetop.
Cover the entire top of the meat mixture with slices of provolone cheese.
Bake the casserole in the oven at 350°F for about 15 minutes or until the top is golden and the cheese is melted. Serve right away.