Cook the Pasta

• Fill a large pot with water and season it generously with salt. Bring it to a rolling boil.
• Add the bucatini pasta and cook until al dente (as per the package instructions, about 8–10 minutes).
• Reserve 1 cup of pasta water, then drain and set the pasta aside.

Prepare the Sausage

• Heat 1 tablespoon of olive oil in a large skillet over medium heat.
• Crumble the Italian sausage into the skillet and cook for 7–10 minutes, stirring occasionally, until browned and fully cooked.
• Transfer the sausage to a plate and set it aside, leaving the flavorful oil in the skillet.

Sauté the Vegetables

• In the same skillet, add the finely chopped onion and cook for about 3 minutes, or until softened.
• Add the diced red and yellow bell peppers. Stir occasionally and cook for an additional 5 minutes, or until the vegetables are tender and slightly caramelized.

Create the Sauce

• Add 1 tablespoon of butter to the skillet with the vegetables and let it melt.
• Stir in the minced garlic and cook for about 30 seconds, or until fragrant.
• Sprinkle the flour over the mixture and stir to combine. Cook for 1 minute to remove the raw flour taste.
• Gradually pour in the heavy cream while stirring to create a smooth sauce.
• Add the Dijon mustard and stir for 2–3 minutes until the sauce thickens slightly.

Combine Ingredients

• Return the cooked sausage to the skillet and stir to coat it in the creamy sauce.
• Add the fresh spinach and stir until it wilts. Season with salt and freshly ground black pepper to taste.

Toss with Pasta

• Add the cooked pasta to the skillet and toss everything together until the pasta is evenly coated in the sauce.
• If the sauce is too thick, gradually add some of the reserved pasta water until you achieve the desired consistency.

Serve and Enjoy

• Plate the pasta and garnish with freshly grated Parmesan cheese, if desired. Serve hot with garlic bread or a green salad on the side.