Preheat your oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper to prevent sticking.
Place the diced zucchini, sliced bell peppers, and red onion onto the sheet pan. Drizzle with avocado oil and sprinkle with sea salt, black pepper, garlic powder, and smoked paprika.
Toss the vegetables until evenly coated, then spread them out in a single layer. Roast for 12-15 minutes until tender and slightly charred.
While the vegetables roast, whisk the whole eggs and liquid egg whites together in a medium bowl until the mixture is uniform and frothy.
Remove the sheet pan from the oven and rearrange the vegetables so they are evenly distributed across the surface.
Carefully pour the egg mixture over the roasted vegetables, ensuring it reaches all corners of the pan.
Return the pan to the oven and bake for an additional 8-10 minutes, or until the eggs are fully set and the edges are slightly golden.
Let the sheet pan cool for a few minutes before slicing into squares and serving.