Step 1: Cook the Pasta

Bring a large pot of salted water to a boil. Add the spaghetti or bucatini and cook until just shy of al dente, about 1-2 minutes less than the package instructions. Reserve 1 ½ cups of the pasta cooking water before draining.

Step 2: Sauté Garlic and Chili

In a large skillet or pan, heat the butter and olive oil over medium heat until melted and bubbling. Add the sliced garlic and sauté until fragrant and lightly golden, about 1-2 minutes. Stir in the crushed chili flakes and cook for an additional 30 seconds to release their flavor.

Step 3: Toast the Pepper

Reduce the heat to low and sprinkle the cracked black pepper into the pan. Toasting the pepper brings out its bold, aromatic qualities, creating a more intense flavor profile for the sauce.

Step 4: Create the Sauce Base

Gradually add about 1 cup of the reserved pasta water to the pan, stirring continuously to create a slightly emulsified base. This helps form the foundation of the creamy sauce.

Step 5: Add the Cheese

Remove the pan from heat and slowly sprinkle in the grated Pecorino Romano and Parmesan, stirring constantly to prevent clumping. The heat from the pasta water will melt the cheese, forming a smooth, glossy sauce.

Step 6: Combine Pasta and Sauce

Add the cooked pasta to the pan, tossing it gently with tongs to coat every strand in the sauce. If the sauce is too thick, add more pasta water, a tablespoon at a time, until the desired consistency is achieved.

Step 7: Adjust and Serve

Taste and adjust the seasoning with more salt, black pepper, or chili flakes if needed. Transfer the pasta to serving bowls, garnish with fresh parsley or basil if desired, and serve immediately with extra grated cheese on the side.