Preheat your oven to 400°F (200°C). This ensures that the vegetables roast evenly and develop a nice caramelization.

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

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

Spread the vegetable mixture evenly on a sheet pan. Make sure they are in a single layer to promote 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. Whisk together until the mixture is well combined and slightly frothy. This helps to incorporate air into the eggs, making them fluffy.

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

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

Return the sheet pan to the oven and bake for an additional 10-12 minutes, or until the eggs are set and the cheese is melted and bubbly.

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

Sprinkle with fresh herbs if desired, then slice into squares or wedges.

Serve warm, and enjoy your delicious sheet pan eggs and veggies!