Ingredients:
2 tablespoons olive oil
2 medium onions, thinly sliced ( 14 oz. total)
2 cloves garlic, minced
1 1/4 lbs ripe tomatoes, cored and cut into 1/4 inch slices
3/4 lb zucchini or 3/4 lb other green summer squash, cut into 1/4 inch slices on the bias ( about 2 small)
3/4 lb summer squash or 3/4 lb golden zucchini, cut into 1/4 inch slices on the bias ( about 2 small)
3 tablespoons olive oil
2 tablespoons fresh thyme leaves
1 teaspoon coarse salt
1 1/4 cups freshly grated parmigiano-reggiano cheese
fresh ground black pepper
Directions:
Preheat oven to 375.
To cook the onions– In a medium skillet, heat the olive oil over medium heat.
Add the onions and saute, stirring frequently, until limp and golden brown, about 2 min.
Reduce the heat to medium-low if they’re browning too quickly.
Add the garlic and saute until soft and fragrant, 1 to 2 min.
Spread the onions and garlic evenly in the bottom of an oiled 2-qt. shallow gratin dish (preferably oval).
Let cool.
To assemble the gratin: Put the tomato slices on a shallow plate to drain for a few minutes and then discard the collected juices.
In a medium bowl, toss the zucchini and squash slices with 1-1/2 Tbs. of the olive oil, 2 Tbs.of the thyme, and 1/2 tsp.of the salt.
Reserve half 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 of the cheese.
Next, lay a row of zucchini, overlapping the tomatoes by two-thirds, and sprinkle with cheese.
Repeat with a row of squash, and then repeat rows, sprinkling each with cheese, until the gratin is full.
Season lightly with pepper and the remaining 1/2 tsp.salt.
Drizzle the remaining 1-1/2 Tbs.olive oil over all.
Combine the reserved cheese with the remaining 1 Tbs. thyme and sprinkle this over the whole gratin.
Cook until well-browned all over and the juices have bubbled for a while and reduced considerably, 65 to 70 min.
Let cool for at least 15 min.before serving.
NOTE: You can use any combination of summer squash for this dish.
Servings: 4-6
Time preparation: 30 min.
Time total: 100 min.