Preheat oven to 350

Lightly butter a deep 2 quart casserole pan

Bring a large pot of salted water to boil over high heat

Add oil and macaroni, cook until mac is almost tender (about 7 mins)

Drain well, return to cooking pot

In a smal saucepan, melt 8 Tbsp butter

In a large bowl, mix the shredded muenster, mild and sharp cheddar, and monterey jack cheeses

To the mac add melted butter, half and half, 1 1/2 cup shredded cheeses, cubed velveeta, and the eggs

Season with salt and pepper, transfer to casserole dish

Sprinkle with remaining shredded cheese and dot with 1 Tbsp butter

Bake for about 35 mins, bubbling around edges