On a baking tray, toss the mushrooms, asparagus, cherry tomatoes, and red onion with olive oil, salt, pepper, and a sprinkle of herbs if you like. Spread the vegetables evenly on the tray and roast for 10 minutes, undisturbed. Once roasted, remove them from the oven and let cool for about 5 minutes.
Reduce the oven temperature to 180°C (350°F) or 160°C fan. Lightly grease a 19 x 30 cm (8 x 10 inch) rectangular baking dish or a 22 cm (9 inch) square pan with oil. Line with parchment paper, leaving a bit of overhang to lift the frittata out later.
In a large bowl, whisk together the eggs, yogurt, milk, salt, and black pepper until smooth and creamy. Stir in half of the shredded mozzarella cheese.
8 Large Eggs, 60 Grams Plain whole milk yogurt, 100 Grams Shredded mozzarella cheese, ½ Teaspoon Salt, ½ Teaspoon Ground black pepper
Spread about two-thirds of the roasted vegetables evenly across the base of the prepared pan.
Pour the egg mixture over the vegetables, then sprinkle over the remaining mozzarella.
Scatter the rest of the roasted vegetables and the crumbled feta on top and finish with crumbled feta cheese.
Bake for 30 minutes, or until the center is just set and the top is lightly golden. A knife inserted into the middle should come out clean.
Allow the frittata to rest in the pan for 5 minutes before lifting it out using the parchment overhang. Slice into squares and serve warm, or enjoy cold for an easy make-ahead meal.
Notes
Tips and Tricks
Mix it up: Swap the vegetables for whatever’s in season, spinach, peppers, zucchini, or even roasted sweet potato work beautifully.
Add protein: Try diced ham, smoked salmon, or cooked bacon for extra richness.
Dairy-free option: Use dairy-free yogurt and cheese for a lighter version.
Meal prep friendly: This frittata keeps well for up to 3 days in the fridge and reheats easily in the oven or microwave.
Freezer tip: Slice, wrap, and freeze portions for up to 2 months. Defrost overnight in the fridge before reheating.
Serving suggestion: Pair with fresh salad greens, avocado, or crusty bread for a balanced, satisfying meal.