01 -
Preheat oven to 175°C. Lightly grease a 23 cm deep dish pie plate.
02 -
Heat olive oil in a large skillet over medium-high heat. Add onion and mushrooms, sauté until softened, about 5–7 minutes. Stir in garlic and cook for 1 minute.
03 -
Turn off heat. Add spinach, crumbled feta, and shredded cheddar to the skillet. Mix to distribute evenly.
04 -
Spoon the vegetable and cheese mixture evenly into the greased pie plate.
05 -
In a mixing bowl, whisk eggs, milk, salt, and pepper until fully combined.
06 -
Pour the egg mixture over the spinach filling in the pie plate.
07 -
Bake in the preheated oven for 40–45 minutes, or until the eggs are set and top is lightly golden.
08 -
Allow to cool for 10 minutes before slicing and serving.