Preheat oven to 325F degrees.
Bring a pot of water to a rolling boil, then add a lot of salt. You want it to be as salty as the ocean tastes. Add pasta and cook pasta to an al dente texture, usually about 7 minutes. Do not fully cook since pasta will cook more later in the oven.
Meanwhile – in a large mixing bowl, add eggs, seasoned salt, and pepper and whisk together. Add milk and whisk again. Set aside.
Drain pasta in a colander. Add butter to pot then return pasta to pot while still hot and mix until butter is completely melted.
Return pot to stove over medium heat. Add cubed cheese and mix until partially melted. Remove from heat.
Add egg/milk mixture to pasta/cheese mixture and stir until well combined. Then pour into 13x9 glass casserole dish.
Bake for 15 minutes. Then remove from oven and gently mix well. Top completely with an even layer of sliced cheddar.
Return to oven and bake for about 15 more minutes. Note: the only thing that needs to cook are the eggs, so resist the urge to overcook.
Remove from oven and let rest for at least 15 minutes (or more) before serving.