2 tbsp (30 mL) olive oil
2 tbsp (30 mL) butter
Half a red onion, chopped
Salt and freshly ground pepper
3 cloves garlic, minced
1 large bunch Swiss chard (to make 1 cup/250 mL chopped stems, plus 4 cups/1 L leaves chopped into 1-inch/3-cm ribbons)
5 eggs
1 cup (250 mL) milk
½ cup (125 mL) mozzarella cheese, grated
½ cup (125 mL) feta cheese, crumbled
One 9-inch (23-cm) unbaked pie crust
Preheat oven to 350 F (175 C). Heat olive oil and butter in a large skillet over medium-high heat. Sauté onion until translucent and just beginning to caramelize, about 10 minutes (lower heat as onion begins to brown.) Season onion with salt and pepper to taste. Add garlic and chopped Swiss chard stems to pan with onion. Sauté about 5 minutes, then cover pan and cook until stems are starting to soften, about another 5 minutes.
Add chopped Swiss chard leaves and sauté mixture until leaves are completely wilted — another 5 to 10 minutes. Set aside.
In a large bowl, whisk eggs. In a glass measuring cup, heat milk in microwave just until steaming, about 1 minute. In a thin stream, whisk hot milk into eggs.
Place unbaked pie crust on a foil-lined pan (in case of spills). Pour egg mixture into pie crust.
Using a slotted spoon so no extra moisture goes into pie from chard mixture, spoon chard mixture evenly into pie.
Sprinkle top with cheeses.
Bake quiche for 30 to 40 minutes, until browned on top and set in the middle. Allow to cool for at least 10 minutes before serving.