Before starting, preheat the broiler to high.Wash and dry all produce. Add 10 cups hot water and 2 tsp salt to a large pot (use same for 4 ppl). Cover and bring to a boil over high heat.Add penne to the boiling water. Cook uncovered, stirring occasionally, until tender, 10-12 min. Reserve 1/4 cup (1/2 cup) pasta water, then drain.

Meanwhile, peel, then mince or grate garlic. Heat a large oven-proof pan over medium-high heat. When hot, add 1/2 tbsp (1 tbsp) oil, then mirepoix. Cook, stirring occasionally, until tender-crisp, 2-3 min. Add beef and 1/2 tbsp (1 tbsp) Italian Seasoning. Cook, breaking up beef, until cooked through, 4-5 min.** Season with salt and pepper.

Add garlic to the pan. Cook, stirring often, until fragrant, 1 min. Reduce heat to medium, then add tomatoes and reserved pasta sauce. Cook, stirring occasionally, until sauce thickens slightly, 3-4 min.

Add penne and 1 tbsp (2 tbsp) butter to the pan with sauce, then stir to combine. (NOTE: If you do not have an oven-proof pan, transfer mixture to a lightly-oiled 8x8-inch baking dish. For 4 ppl, use a 9x13-inch baking dish.) Remove the pan from heat. Top with mozzarella and half the Parmesan cheese. Broil in the middle of the oven until cheese melts, 4-5 min.

Divide pasta between plates. Sprinkle remaining Parmesan cheese overtop.