Prepare noodles according to the directions on the packaging, season with salt, and cook until al dente.
Preheat the oven to 350 F.
Chop your onion and shred your cheese.
Measure out your butter, milk, and panko crumbs, separately, and set aside.
Once the noodles are cooked, strain off the water.
Prepare a large
rectangular baking dish by spraying it with oil.
Add a thin layer of cooked noodles, followed by a thin layer of onion, followed by a thick layer of cheese, a ¼ of the panko measured out, ¼ of the milk measured out, garnish with black pepper, and repeat this step 2 more times.
Top the final layer with chunks of butter, and all remaining ingredients (panko, milk, black pepper, and onion).
Bake for 40 mins, covered. Remove the tin foil, and bake for additional 8-10 minutes until the cheese starts to brown.
Remove from oven and let the casserole rest for 20 minutes before serving.