Preheat your oven to 400°F and line a small baking sheet with parchment paper.
Toss the sliced red bell peppers and onions with half of the ghee, garlic powder, and a pinch of salt.
Roast the vegetables for 15 minutes until they are tender and show slight charred edges.
In a small bowl, whisk together the whole egg and egg whites with the remaining salt and pepper.
Heat the remaining ghee in a non-stick skillet over medium heat, pour in the egg mixture, and cook until set, folding it into a square shape.
Slice the chicken sausage links lengthwise and sear them in the skillet for 2-3 minutes per side until golden brown.
Toast the sprouted grain bun until it is warm and slightly crispy.
Assemble the sandwich by placing the baby spinach on the bottom bun, followed by the egg patty, seared sausage, and the roasted pepper and onion mixture.