Heat olive oil in a skillet over medium heat. Sprinkle both sides of the tilapia fillets with Chinese five-spice powder, salt, and black pepper; cook tilapia fillets in the skillet until lightly browned and the flesh is white and opaque, about 3 minutes per side. Remove from heat.
Place the spinach leaves into a large salad bowl, and top with the orange bell pepper, grapefruit, tomato, and avocado. Drizzle the salad with the Asian-style dressing, sprinkle with almonds, and top with the cooked tilapia fillets.