|Summer Squash Gratin with Parmesan and Thyme
5 TBS olive oil, divided
2 medium onions, thinly sliced
1 1/4 lb. Small, ripe tomatoes, cored and cut into 1/2 inch slices
3/4 lb. (about 2 small) zucchini
3/4 lb. (about 2 small) yellow squash
1/4 cup fresh thyme leaves
1/4 cup coarse salt
1 1/4 cup grated Parmigiano-Reggiano cheese
freshly ground black pepper to taste
Tony’s Homemade Croutons
Sauté onions with 2 Tbsp. olive oil and sauté until golden brown. Spread the onions into the bottom of a shallow glass or ceramic gratin dish. Heat the oven or grill to 375 degrees.
Allow the tomatoes to drain and discard juices. In a medium bowl, toss the squashes with 1 1/2 TBS of the olive oil, 2 TBS of the thyme and 1/2 tsp of the salt. Reserve 1/2 of the cheese for the top of the gratin. Sprinkle 1 TBS of the thyme over the onions in the gratin. Starting at one end of the baking dish, lay a row of slightly overlapping tomato slices across the width of the dish and sprinkle with a little cheese. Next, lay a row of the zucchini , overlapping the tomatoes by 2/3, and sprinkle with cheese. Repeat with a row of yellow squash and then repeat rows, sprinkling each with cheese until the dish is full.
Season lightly with pepper and the remaining 1/2 tsp. of salt. Drizzle the remaining 1 1/2 TBS olive oil over all. Combine the reserved cheese with the remaining thyme and sprinkle over the gratin. Cook for 50 - 60 minutes until the juices have reduced considerably. Top with a layer of crispy crouton topping and return to oven until nicely browned. Allow to cool 10-15 minutes before serving.