Tomato and Onion Quiche with Colby and Parmesan

I love the simplicity and fresh taste of tomatoes with a sprinkling of basil. It makes for a lovely light lunchtime treat.
1 (9”) deep dish pie crust, unbaked
1 Tbsp. extra-virgin olive oil
1 onion, sliced
2 tomatoes, peeled and sliced
2 Tbsp. all-purpose flour, unbleached
2 Tbsp. fresh basil, chopped or torn
3 eggs, beaten
½ cup heavy cream
½ tsp. sea salt
½ cup Colby-Monterey Jack cheese, shredded, divided
¼ cup Parmesan cheese, freshly grated
Preheat oven to 400°F (200°C/180°C fan, Gas Mark 6). Bake pie shell in preheated oven for 8 minutes.
Meanwhile, heat olive oil in a large skillet over medium heat. Sauté onion until soft, remove from skillet. Sprinkle tomato slices with flour and basil, then sauté 1 minute on each side. In a small bowl, whisk together eggs and milk. Season with salt and pepper.
Spread ½ cup cheese, shredded in the bottom of pie crust. Layer onions over cheese, and top with tomatoes. Cover with egg mixture. Sprinkle top with parmesan cheese.
Bake in preheated oven for 10 minutes.
Reduce heat to 350°F (180°C/160°C fan, Gas Mark 4), and bake for 15-20 minutes, or until filling is puffed and golden brown.
Serve warm.
Makes 4-6 servings.