Preheat your oven to 400°F (200°C). This high temperature will help the vegetables roast quickly and develop a nice caramelization.

In a large mixing bowl, combine the diced bell peppers, zucchini, halved cherry tomatoes, and chopped spinach.

Drizzle the olive oil over the vegetables and sprinkle with salt, black pepper, and garlic powder. Toss everything together until the vegetables are evenly coated.

Spread the vegetable mixture evenly on a sheet pan. Make sure they are in a single layer for even roasting.

Roast the vegetables in the preheated oven for 15 minutes, stirring halfway through to ensure even cooking.

While the vegetables are roasting, crack the eggs into a mixing bowl.

Add the milk, salt, and black pepper to the eggs. Whisk vigorously until the mixture is well combined and slightly frothy. This aeration will make the eggs fluffy.

After the vegetables have roasted for 15 minutes, remove the sheet pan from the oven.

Pour the egg mixture evenly over the roasted vegetables. If using, sprinkle the shredded cheddar cheese on top.

Return the sheet pan to the oven and bake for an additional 10-15 minutes, or until the eggs are set and lightly golden on top.

To check if the eggs are done, gently shake the pan; the eggs should not jiggle in the center.

Once baked, remove the sheet pan from the oven and let it cool for a few minutes.

Slice into squares or wedges and serve warm. Enjoy your delicious and nutritious sheet pan eggs and veggies!