I used Vivian Howard’s recipe for tomato pie as a starting point. I don’t make my own crust and I have modified it a little bit. Thyme is too subtle a flavor and I can’t taste it with all the other stuff. So, I leave it out.
Filling and topping:
2 tablespoons olive oil
1 medium yellow onion, halved and cut into julienne with the grain
2 teaspoons salt, divided
3 ½ pounds tomatoes, cut into ½-inch dice,
1 teaspoon granulated sugar
2 tablespoons extra-virgin olive oil
½ teaspoon black pepper
⅓ cup picked basil leaves (3 Tbsp dried)
¼ cup mayonnaise
⅓ cup grated Fontina
⅓ cup grated Parmigiano-Reggiano
Blind-bake your crust for for 2/3 of the time required by your crust recipe (or box directions) until it is slightly underdone.
In a medium saute pan or skillet, heat the oil and add the onions and ½ teaspoon salt. Cook the onions over medium-low heat till they are deeply caramelized. This will take about 40 minutes. If your onions get away from you and burn a little, add ¼ cup of water to the pan, scrape up the over-browned bits, and keep going, In the end, you’ll have a scant ⅓ cup caramelized onions.
Toss the tomatoes with ½ teaspoon salt and ½ teaspoon sugar. Set them over a colander and let them drain while you get everything else ready, at least 30 minutes.
Once all the individual components are done, stir together the onions, the tomatoes, the salt and sugar, black pepper and basil. In a separate, smaller bowl, stir together the mayonnaise, Fontina, and Parmesan.
Spoon the filling into your blind-baked crust and crown it with mayo-and-cheese topping. Bake in the middle rack of your oven for 30 – 45 minutes at 325ºF until the top is a nice golden brown. Let cool a while (30 minutes?) before you serve it.
If you want to, you can freeze fresh-from-your-garden tomatoes in a gallon bag, cut in quarters. Thaw them and drain them and continue from there. Whichever way you prepare the tomatoes, get them as dry as you can before you put them in the crust.