Preheat the oven to 375 degrees F or 190 degrees F. Grease a 9×13 inch baking dish.
Place the tilapia fillets in the bottom of the baking dish and dot them with butter.
In a small bowl, mix the butter, lemon juice, red pepper flakes garlic powder and salt; then pour over the fillets.
Top each tilapia with a slice or two of lemon. Sprinkle with capers, oregano and paprika.
Arrange the frozen mixed vegetables around the fish, and season lightly with salt and pepper.
Bake, uncovered, at 425° for 20 minutes in the preheated oven, until vegetables are tender and fish flakes easily with a fork.
Serving Suggestions: Serve immediately, garnished with parsley, if desired. Tender potatoes go wonderfully with baked tilapia, and you may add a green salad too.