Preheat your oven to 375 degrees Fahrenheit and lightly grease a 9x13-inch baking dish. I usually use a quick spray of cooking oil or a thin coating of butter.

Place your tilapia fillets in a single layer across the bottom of the prepared baking dish, leaving a little space between each piece. Pat them gently with a paper towel if they seem wet.

Dot each fillet with small pieces of butter, then sprinkle the garlic salt and seafood seasoning evenly over the top. Don't worry about being too precise here; just distribute the seasonings so each fillet gets its fair share of flavor.

Top each tilapia fillet with one or two fresh lemon slices. These will infuse the fish with bright, citrusy flavor as everything bakes together.

Scatter the frozen mixed vegetables around the fish fillets, filling in the spaces in the baking dish. Season the vegetables lightly with salt and freshly ground black pepper.

Cover the entire baking dish tightly with aluminum foil. This traps steam inside, helping the fish stay moist and the vegetables cook through properly. Slide the dish into your preheated oven and bake for 25 to 30 minutes, until the vegetables are tender and the fish flakes easily when tested with a fork.

Remove the foil carefully (watch out for that hot steam), plate your beautiful baked tilapia with the vegetables, and serve immediately while everything is hot and fragrant.