Boil the pasta: Bring a large pot of salted water to a boil. Add the pasta and cook until al dente. Reserve 1 to 1.5 cups of starchy pasta water before draining.

Start the sauce base: In a wide skillet over medium heat, melt the butter with a splash of olive oil (optional, helps prevent scorching). Add the minced garlic and a pinch of red pepper flakes if using. Cook 60–90 seconds, just until fragrant. Do not brown the garlic.

Build the creaminess: Lower the heat and pour in the milk, half-and-half, or cream. Whisk to combine with the butter-garlic mixture. Simmer gently for 1–2 minutes until slightly thickened.

Season early: Add a good pinch of salt and several grinds of black pepper. Taste the sauce—this is where you set the foundation.

Add cheese for body: Sprinkle in the grated Parmesan a little at a time, whisking until smooth. The sauce should be silky, not gloopy. If it tightens up, loosen with a splash of pasta water.

Toss with pasta: Add the drained pasta straight into the skillet. Toss and toss again, adding reserved pasta water as needed until the sauce clings lightly to each strand. Glossy, not soupy is the goal.

Brighten it up: Zest in a little lemon and add a small squeeze of juice if you like. Fold in chopped parsley or chives for freshness.

Final taste check: Adjust salt, pepper, and heat (more red pepper flakes if you want). If it feels heavy, add a splash of pasta water or an extra squeeze of lemon.

Serve immediately: Twirl into warm bowls and finish with extra Parmesan and a crack of black pepper.