Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Place the cubed chicken breast, trimmed asparagus, and diced bell peppers onto the sheet pan.
Drizzle with olive oil and lemon juice, then sprinkle with dried oregano, garlic powder, sea salt, and black pepper.
Toss everything directly on the pan until evenly coated, then spread into a single layer.
Roast in the oven for 15 minutes until the chicken is cooked through and the vegetables are tender.
Remove the pan, push the chicken and veggies to one side, and pour the egg whites onto the empty space.
Return to the oven for 4 to 5 minutes until the egg whites are fully set and opaque.
Scramble the eggs slightly with a spatula and toss everything together before serving warm.