Heat a pot of water until it boils, then add 14 oz spaghetti. Cook until al dente, following the packaging instructions. Quickly rinse the pasta with cool water to prevent overcooking and clumping.

Trim off the stem of the onion, then peel away the skin. Split the onion in half lengthwise. Make thin vertical cuts into each half while leaving the root intact. Next, cut horizontal slices from the bottom to the top of the onion. Finally, slice downwards to dice the onion into smaller chunks.

Finely mince the garlic.

Finely chop the parsley.

Preheat the oven to 400°F.

Sauté the garlic: Place a shallow pan over medium heat. Add 1 tbsp unsalted butter and 1/2 tbsp minced garlic. Sauté until fragrant, about 30 seconds.

Make the cream sauce: In the same pan, add 2 1/2 tbsp all-purpose flour, stir to make a roux. Slowly stir in 1 cup whole milk and 1/4 tsp salt. Lower heat setting to low, and stir frequently for five minutes, or until thickened. Remove from heat.

Cook the beef: Heat 1 tbsp olive oil in another frying pan over medium heat. Stir in 1/2 tbsp garlic and 2 oz diced onion, then sauté for 1 minute. Add 6 oz 85% lean ground beef and stir to cook for another 3 minutes.

Incorporate the tomato sauce and the seasonings: To the beef, add 3/4 cup homemade tomato sauce, 1/2 tbsp all-purpose flour, 1/2 tsp paprika, 1/2 tsp garlic powder, 1/2 tsp salt, and 1/2 tsp pepper. Stir continuously for 3 minutes.

Assemble all the ingredients: In a baking casserole dish, layer 14 oz cooked spaghetti, pour in the beef mixture and top it with the cream sauce. Make sure each layer is evenly spread.

Bake the spaghetti casserole: Put the baking dish in the middle rack of the oven and bake at 400°F for 15 minutes. Take it out and sprinkle on 2 oz shredded cheddar cheese. Switch oven to broil and place dish on top rack for approximately three minutes, or until cheese is melted. Remove from the oven.

Garnish and serve: Transfer your desired portion onto a platter. Garnish with 2 tbsp chopped parsley. Enjoy.