4 c thinly sliced zucchini and/or summer squash
1 medium onion, halved, then sliced
2 T butter or olive oil
1/2 c grated Parmesan cheese, divided
1 – 1-1/2 lbs ground beef (or turkey, pork, lamb, crumbled firm tofu, crumbled tempeh…)
1 T flour
1 t salt
pepper, to taste
2/3 c ketchup or tomato sauce
ketchup, or additional tomato sauce, for serving, optional

1. Preheat oven to 350ºF.

2. In a large skillet, saute zucchini and onion in butter until onion is tender, about 8 minutes. Pour into a large baking dish. Sprinkle with 1/4 c of Parmesan cheese. Set aside.

3. In the same skillet, brown ground beef. Take off heat. Drain excess fat (if any). Stir in flour, salt, and pepper. Then add ketchup or tomato sauce and stir to combine. Spoon meat mixture over zucchini and onions. Cover and bake for 20 minutes.

4. Remove cover and top with remaining 1/4 c Parmesan cheese. Bake, uncovered, an additional 5 minutes or until cheese is lightly browned. Cut into squares to serve. Pass ketchup and additional tomato sauce at table, if using.