4 medium russet, red or yellow potatoes
1 1/2 tablespoons olive oil, divided
1 zucchini, sliced
1 yellow summer squash, sliced
1/2 pound sliced mushrooms
1 small yellow onion, sliced
Salt and pepper to taste
1 cup marinara sauce
1/2 cup shredded mozzarella
Preheat oven to 400°F. Prick potatoes all over with a fork, brush with 1/2 tablespoon of the oil and arrange on a small baking sheet. Bake until tender, 1 to 1 1/2 hours.
When the potatoes are almost tender, heat remaining 1 tablespoon oil in a large skillet over medium high heat. Add zucchini, squash, mushrooms, onions, salt and pepper and cook, stirring occasionally, until just tender and golden brown, 6 to 8 minutes.
Preheat broiler. Split open potatoes, transfer to a baking dish and top with zucchini mixture. Pour marinara over potatoes then top with mozzarella. Broil until cheese is melted and bubbly, 2 to 3 minutes, then transfer to plates and serve.
Per serving (1 potato): 340 calories (90 from fat), 10g total fat, 2.5g saturated fat, 10mg cholesterol, 670mg sodium, 53g total carbohydrate (8g dietary fiber, 11g sugar), 12g protein