👩🍳 Instructions
1
Boil a large pot of water, salt it generously, and cook 12 oz spaghetti until al dente. Reserve 1/2 to 1 cup pasta water, then drain.
2
Heat a large skillet over medium-high heat. Add 1 lb ground beef in an even layer and let it sear for 2–3 minutes before breaking up. Brown until caramelized, about 6–8 minutes. Add diced onion in the last 2–3 minutes.
3
Push beef to the side, reduce heat to medium, and add 2 tbsp butter to the cleared space. Once melted and foamy, add minced garlic and red pepper flakes; stir 30–45 seconds until fragrant without burning.
4
Deglaze the pan with 1/2 cup white wine or beef broth, scraping browned bits. Reduce liquid by half.
5
Remove from heat, stir in remaining 2 tbsp butter, 1/2 cup grated Parmesan, and a splash of reserved pasta water. Toss until a glossy sauce forms. Add pasta and toss to coat, adding more pasta water as needed to reach desired consistency.
6
Season with salt, pepper, lemon zest if using, and chopped parsley. Serve with extra Parmesan and a drizzle of olive oil if desired.
