Preheat the oven to 400 degrees. Line a baking sheet with tin foil then coat with cooking spray.
Remove the stem and gills from the mushroom. Rub the portobello with a bit of olive oil then season both sides with sea salt, freshly cracked pepper, and garlic powder, to taste. Sprinkle the inside of the mushroom with some roasted red pepper and feta cheese then add a pinch of crushed red pepper on top.
Place into the oven and bake for 7 minutes. Remove from the oven and crack the egg into the center of the mushroom.
Place back into the oven and cook for 13-15 minutes, or until the whites are cooked and the yolk is runny. Remove from the oven and place on a plate sprinkle some chopped basil on top. Serve immediately. Enjoy.