Mash: Boil potatoes in salted water until tender (15 mins). Drain and mash with butter, milk, salt, and pepper.
Filling: While potatoes boil, brown beef and onion in a large oven-safe skillet on Level 7 (Medium-High). Drain fat. Simmer: Add carrots, broth, tomato paste, and spices. Simmer for 5-7 mins until carrots soften slightly. Stir in frozen peas.
Bake: Spread mashed potatoes over the beef mixture. Bake at 400°F for 20 minutes until the top is golden.