Cook the Pasta
Bring a large frying pan of well salted water to the boil.
Cook the bucatini about 3 minutes short of al dente.
Reserve 1 cup of pasta water, then drain the pasta.
Make the Garlic Oil
While pasta cooks, heat olive oil in a large skillet/saucepan over medium-low heat.
Add red pepper flakes and sauté for 30 seconds to get the heat into the oil
Add garlic and cook gently for 2 minutes, until just golden and fragrant. Do not let it brown.
Combine and Emulsify
Add drained pasta to the skillet with the garlic oil.
Toss or stir vigorously while gradually adding reserved pasta water.
Continue tossing/stirring until a light, glossy sauce forms (this is called mantecatura).
Finish and Serve
Remove from heat. Stir in chopped parsley.
Season with salt and black pepper to taste.
Optional: Add grated Parmesan and/or lemon zest for extra depth.
Serve immediately.