Preheat your oven to 350 degrees Fahrenheit.
Prepare your baking pan by greasing it with the butter and then spraying it with some vegetable oil spray. Set aside.
1 tsp butter, vegetable oil spray
In a mixing bowl combine the eggs with the milk and yogourt and whisk until very well combined.
8 large eggs, ¼ cup (60 mL) milk, 1 tbsp Greek yogourt, plain
Squeeze out as much water as you can from the zucchini (using either your hands, a cheesecloth or clean kitchen towel).
1 cup (133 grams) grated zucchini
Add the drained zucchini, red pepper, mozzarella cheese, salt and pepper to the egg mixture and whisk until well combined.
1 cup (133 grams) grated zucchini, 1/2 cup diced red pepper, ½ tsp salt, ¼ tsp pepper, ½ cup shredded mozzarella
Pour into your prepared baking pan and bake, uncovered, in the middle rack of your oven for 18 - 20 minutes.
Test for doneness by ensuring that the egg is set (touch the top with your finger) and slightly brown around the edges.
Allow to cool and cut into 6 equal pieces.