Tarte courgette-oignon rouge

Zucchini-red onion tart

This makes a fine light dish or starter on a summer’s day, when zucchini are at their finest. Preparation takes about an hour, including baking, or a bit more if you make your own pie crust (better). But sometimes it’s too hot to spend time in the kitchen, in which case it’s fine to use a high-quality store-bought pie crust, which I did in the tart pictured above.

For best results, use the freshest possible zucchini (but stay away from the humongous kind that can turn up at farmers markets in late summer). Also, this recipe calls for grated cheese. I used Comté, and any similar cheese would be fine. You could also substitute goat cheese (chèvre), which needs to be crumbled or finely sliced instead of grated.

You will need a 9-10 inch (22-25 cm) tart or pie pan. The tart will serve 6-8 people, and can be nicely accompanied by a salad of tender leaves.

1 unbaked pie crust (pâte brisée), store bought or homemade
I medium or 2 small zucchini (about 10 ounces / 300 g)
1 large or 2 medium red onions (same weight as the zucchini)
3 tsp. olive oil
1 tsp. butter (1/2 ounce / 15 grams / 1 pat)
1 branch fresh thyme or 1/2 tsp. dried thyme
2 eggs
1/2 cup crème fraîche or heavy cream (4 ounces / 115 g)
1/4 cup milk (6 cl)
2 ounces (60 g) Comté, Gruyère or a similar cheese
salt and freshly ground black pepper

Start with the pie crust. If making it yourself, follow the recipe and pat it into your tart pan. If using a store-bought crust, unroll it and pat into your tart pan. There will be excess dough around the edges. Fold it in over itself to make a rim, then flute by pinching the rim between your thumbs and forefingers, working your way around the pan. Important: do not prick the dough.

Place the tart shell in the fridge to chill while you proceed with the recipe.

Rinse the zucchini and slice into rounds (not too thin). Chop off the ends of the onion, cut in half lengthwise, peel and slice into half-rounds (again, not too thin).

In a large skillet, heat 2 tsp. olive oil to sizzling. Add the zucchini and sauté, stirring, until the rounds are just starting to brown, about 5 minutes. Remove to a bowl. Sprinkle with salt and grind on some black pepper.

Add 1 tsp. olive oil and the butter to the same skillet. Add the onions. Sprinkle with the thyme. Sauté, stirring, until the onions are wilted and starting to brown, 5-10 minutes. Turn off the heat. Sprinkle with salt and grind on some black pepper.

Preheat your oven to 180 C (350 F, gas mark 6).

Crack the eggs into a medium bowl. Whisk. Add the cream, milk and a pinch of salt.  Grind on some black pepper. Whisk to blend thoroughly.

Grate the cheese, using the large holes of your grater.

Now for the fun part, assembly. Retrieve your pie shell from the fridge. Place a layer of zucchini on the bottom (use about 2/3). Strew the onions over the zucchini, then place the rest of the zucchini on top. Sprinkle with the grated cheese. Drizzle with the egg mixture.

Bake for 25-30 minutes, until the cream has set and the tart is golden brown.

Serve the tart warm or at room temperature, on its own or accompanied by a salad. A chilled rosé would go nicely. Serves 6-8.