Such a quick and delicious dish. This is inspired by Ina Garten's Panko-Crusted Salmon, although I modified it to use ingredients I already had in my kitchen and to use slightly less oil. It was absolutely perfect paired with roasted asparagus.
In a shallow bowl, mix panko, garlic, thyme, cayenne, and a generous pinch of both salt and pepper. Add the olive oil to panko mixture, mixing with fingers so that breadcrumbs are evenly coated. Set aside.
Spray a baking sheet with non-stick cooking spray. Place tilapia fillets on baking sheet at least 1 inch apart. Spread 1/2 tsp dijon mustard (or more to taste) evenly on each fillet. Press panko mixture on top of the mustard, splitting the panko evenly among the four fillets.
Bake for 10-12 minutes, until fish is cooked through and will flake with a fork.