Preheat the oven to 180°C (375°F). Lightly brush a muffin tin with extra virgin olive oil.
Halve the cherry tomatoes, scoop out and discard the seeds, then finely chop the remaining flesh.
In a large bowl, beat the eggs with a fork. Add the chopped spinach, chopped tomatoes, sliced mushrooms, cubed zucchini, grated Parmesan, salt, and pepper and mix until combined.
Fold the cooked quinoa into the vegetable and egg mixture until evenly incorporated.
Spoon the mixture into the prepared muffin tin, filling each cup evenly.
Bake for 10–12 minutes, or until the tops are golden and the muffins are set.
Remove from the oven and allow to cool slightly before removing from the tin and serving.