To prepare tilapia , preheat oven to 375 F. spray a tinfoil lined baking sheet and set aside.
Place fish fillets in a baking dish. Pour lemon juice over it. season with salt and black pepper on both sides.
Place pumpkin seeds, cereal, oregano leaves in a bowl of food processor and pulse until the mixture is coarsely ground. Season to taste with salt and black pepper and garlic powder( be careful about how much salt you put as you already seasoned the fish before).
Arrange the fish on prepared baking tray. Spoon Pepita mixture on each fillet, spread to cover the fish and pat lightly. Spray with oil.
Bake for about 10-12 minutes or until they easily flake with a fork and edges are browning. while the tilapia is in the oven, prepare mango salsa.
Combine the mango, red pepper, onion,green chilli and cilantro in a bowl.
Add lemon juice and toss well. Season with salt and black pepper.
Serve crusted Tilapia with mango salsa on top.