Season Tilapia fillets lightly with salt and pepper. Combine pecans, bread crumbs,chopped rosemary, granulated garlic, salt and pepper in a small bowl and mix well.
In a shallow dish, place beaten egg and water. Place half of the Pecan mixture in another shallow dish. Dip seasoned fillets in the egg mixture, allowing excess to drip away, then place in the pecan-crumb mixture and dredge carefully, making sure that both sides of fish is coated evenly. Place fillets on a wire rack to allow coating to dry slightly before going into the oven.
Melt butter in a large oven-proof skillet(I used a 12" skillet). Place fillets in skillet; try not to crowd them too close together. Drizzle a little melted butter over the top of each fillet.
Place in preheated oven and bake for 8 to 10 minutes, or until fish flakes easily with a fork.