Eggplant Gratin with Saffron-Ricotta Custard
2 pounds small globe or larger oblong eggplants
Vera Jane’s Extra-Virgin Olive Oil
1 small red onion, finely diced
1 large clove garlic, minced
½ tsp herbes de Provence
2 ½ pounds ripe full-sized tomatoes, peeled, seeded, and chopped or 2 cups crushed canned tomatoes
Sea salt and freshly ground pepper
1 cup ricotta
¼ cup milk
1 good pinch saffron threads, crumbled and soaked in 1 tablespoon hot water
½ cup freshly grated Parmigiano-Reggiano
½ cup gruyere, grated (optional)
10 large basil leaves, torn into pieces
Heat oven to 400 degrees.
Cut the eggplants in half, lengthwise. If eggplants are large, cut into quarters. Slice each piece crosswise about ½-inch thick. Brush the slices lightly with the oil, set them on a sheet pan, then bake until the bottom sides have browned, about 15 minutes. Turn them over and brown the second side; bake an additional 8-15 minutes. When the eggplant is done, remove it from the oven and reduce the heat to 350 degrees.
To make the tomato sauce, warm 2 tablespoons of olive oil in a wide skillet. When hot, add the onion, garlic, and herbes de Provence (crushed first between your fingers). Stir to coat the onion with the oil, then reduce the heat to medium-low, and cook slowly until it is soft, 12 – 15 minutes. Add the chopped fresh or canned tomatoes, raise the heat, and cook, stirring occasionally, until the liquid has cooked off and the sauce is fairly thick. Season to taste with salt and pepper.
To make the custard, whisk the eggs and stir in the ricotta, milk, saffron, and Parmigiano-Reggiano. Season with a few pinches of salt and some freshly ground pepper.
Spread a cup of the sauce in a casserole dish ( 8-cup capacity, 2-inch sides, or a larger (8X12-inch dish, allowing the ingredients to spread to a thin layer along with the custard topping), and then set down an overlapping layer of eggplant. Season it with salt and pepper. Scatter half the torn basil over the surface. Dab about ¼ cup of the sauce over the eggplant and then make another layer of eggplant, season with salt and pepper and torn basil, and cover with the rest of the tomato sauce. Sprinkle the gruyere cheese over the tomato sauce (if using) and pour the custard over all and bake until it has gently swelled and is browned in places, about 40 minutes.
Remove from the oven and let the gratin rest for about 20 minutes before serving.