1 pound cavatappi pasta (corkscrew)
2 tbsp EVOO
2 large onions, thinly sliced
Pepper
3 tbsp butter
3 tbsp flour
2 cups shredded provolone
3 cups milk
1/2 cup beef stock
3/4 pound thinly sliced roast beef, coarsely chopped
1/4 cup parsley, chopped

Bring large pot of water to boil. Salt, add pasta and cook. Drain and return to pot.

While pasta is coming to boil, heat EVOO in a large skillet on medium to medium-high heat. Add onions and pepper and cover with a lid or aluminum foil for 2-3 minutes. Remove lid and continue cooking until tender and lightly carmelized, 12-15 minutes, stirring occasionally.

While onions are carmelizing, melt butter in a medium pot over medium-high heat. Sprinkle flour over melted butter and cook for about 1 minute, stirring constantly. Whisk milk into mixture slowly and bring to a bubble to thicken, about 5 minutes. Remove pot from heat and stir in 1 1/2 cups of cheese, then season with pepper and reserve.

Preheat broiler.

To skillet with onions, add beef stock and roast beef. Stir over medium heat just to warm through.

Add cheese sauce and onion-roast beef mixture to the pot with drained pasta and toss to combine. Return to 9×13 casserole dish and top with remaining cheese. Broil until bubbly, 2-3 minutes. Garnish with parsley.