Bring 4 liters of water to a rolling boil in a large pot. Add 2 tablespoons kosher salt. Add 1 lb dried spaghetti or linguine and cook according to package for al dente (typically 8–10 minutes). Reserve 1 cup of pasta cooking water, then drain pasta and toss with 1 tablespoon olive oil to keep strands separate. Keep warm.

Tomato Sauce (Marinara)

Heat 2 tablespoons olive oil in a medium saucepan over medium heat. Add 1 cup finely diced onion and sauté until translucent, about 5–6 minutes. Add 4 teaspoons minced garlic and cook 30 seconds until fragrant.

Stir in 2 tablespoons tomato paste and cook 1 minute to deepen flavor. Pour in 28 oz crushed tomatoes, 1 teaspoon sugar (if using), 1 teaspoon dried oregano and 1 teaspoon salt, 1 teaspoon freshly ground black pepper and 1 teaspoon red pepper flakes (optional). Bring to a gentle simmer.

Reduce heat to low and simmer, uncovered, 15–20 minutes, stirring occasionally, until slightly thickened. Taste and adjust salt, sugar or red pepper flakes. Stir in 6 torn basil leaves just before serving. Keep warm.

Creamy Alfredo Sauce

In a medium skillet over low-medium heat, melt 4 tablespoons unsalted butter. Add 2 teaspoons minced garlic and cook 30 seconds until fragrant but not colored.

Pour in 1 cup heavy cream and bring to a gentle simmer, stirring. Reduce heat to low and whisk in 1 cup finely grated parmesan cheese in two additions until smooth. Season with 1 teaspoon salt, 1 teaspoon freshly ground black pepper and 1/4 teaspoon freshly grated nutmeg (optional). If sauce seems too thick, loosen with up to 1/4 cup reserved pasta water. Keep warm.

Protein Toppings

Cook chicken: Toss 1 lb sliced chicken breast with 1 tablespoon olive oil, 1/2 teaspoon salt, 1/2 teaspoon black pepper and 1 teaspoon Italian seasoning. Heat a large skillet over medium-high heat and sear chicken in a single layer 3–4 minutes per side until cooked through and golden. Remove and keep warm, slice into bite-sized pieces if desired.

Cook sausage: In the same skillet over medium heat, add crumbled 12 oz Italian sausage. Break up with a spatula and cook until browned and cooked through, about 6–8 minutes. Transfer to a bowl and keep warm.

Vegetable Toppings

Sauté mushrooms and peppers: Heat 1 tablespoon olive oil in a skillet over medium-high heat. Add 8 oz sliced mushrooms and 1 cup thinly sliced red bell pepper. Season with 1/2 teaspoon salt and 1/4 teaspoon black pepper. Cook, stirring occasionally, until vegetables are browned and tender, about 6–8 minutes. Remove and keep warm.

Wilt spinach: In the same skillet, add 4 cups baby spinach and cook 1–2 minutes until just wilted. Season lightly with a pinch of salt. Remove and keep warm.

Finish & Assemble

Set up a pasta bar: Place warm pasta in a large serving bowl or on a platter. Place marinara and alfredo sauces in separate warm bowls. Arrange chicken, sausage, mushrooms, peppers, wilted spinach, grated parmesan, red pepper flakes, chopped parsley and pine nuts in small bowls or on a platter for guests to build plates.

To serve individually: For a single composed dish, toss a portion of hot pasta (about 2 cups cooked) with 1/2 cup marinara or 1/2 cup alfredo (or a mix), using reserved pasta water a tablespoon at a time to achieve desired consistency. Top with desired proteins and vegetables. Finish with 2 tablespoons grated parmesan, a sprinkle of parsley and a pinch of red pepper flakes or pine nuts as desired.

Serve immediately so sauces stay warm and pasta remains al dente.