Cook risotto according to package directions, adding mushrooms and shallots with the water.
Meanwhile, sprinkle tilapia with seafood seasoning. In a large nonstick skillet, heat 2 tablespoons butter over medium heat. In batches, cook tilapia with garlic until fish just begins to flake easily with a fork, about 5 minutes, turning fillets halfway through cooking.
Stir cheese and remaining butter into risotto; remove from heat. Serve with tilapia.