Cook the pasta

• Bring a large pot of salted water to a boil.
• Cook the spaghetti until al dente, then reserve a cup of the pasta water before draining.

Make the lemon garlic base

• Warm the olive oil and butter in a pan over low heat.
• Add the minced garlic and cook gently until fragrant, without browning.
• Stir in the lemon zest.

Build the silky sauce

• Add a splash of the reserved pasta water to the pan.
• Whisk in the grated parmesan until melted and smooth.
• Stir in the lemon juice and season with black pepper.

Toss and serve

• Add the drained spaghetti to the pan and toss with tongs until every strand is coated.
• Loosen with more pasta water if needed.
• Serve immediately with extra parmesan and lemon zest.