Preheat oven to 400°F with pizza stone or flat baking sheet inside oven.
Heat medium sauté pan. Add olive oil, then sliced mushrooms and onions. Cover and cook for 5-10 min on medium heat until caramelized.
Brush the pizza crust with pesto. Sprinkle cooked down mushrooms and onions, then a light layer of cheese. Then sprinkle olives and chicken strips, and then finish with sprinkling rest of cheese over toppings.
Bake in the oven, on pizza stone or baking sheet, for 15-20 minutes or until the edges becomes lightly brown and crisp.
Remove from oven, top with basil and chili flakes, and cut into slices or squares for the perfect appetizer.