1. Melt garlic butter in a small saucepan over low heat. Allow butter to simmer for one to two minutes after it’s melted until it begins to turn golden. Don’t raise the heat. Watch the pot carefully to avoid burning. (If using regular butter, brown the butter in a saucepan. Remove from heat and immediately add one clove crushed garlic. Swirl the pan and the garlic will become fragrant.)
2. Add the lemon juice to browned butter and set aside. Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).
3. Rinse the fish and dry. Slice each fillet in half lengthwise, then into three slices on the width, yielding six one-inch (two centimeter) cubes per fillet. Sprinkle fish with salt and pepper.
4. Arrange the fish in a lined baking pan and pour the lemon-butter mixture on top.
5. Wipe the saucepan (no need to wash it out) and prepare the topping: Melt butter, then add panko crumbs and Parmesan cheese. Stir until combined and slightly toasty. Remove from heat and divide the topping evenly over the tilapia bites. Place in the oven and bake for 12 minutes.
6. Allow to cool, then transfer to a serving plate. Insert decorative toothpicks before serving.