• Prepare Ingredients: Thinly slice the leek, mince the garlic, and cut the broccoli into small florets. Set aside.
• Cook Leek and Garlic: In a large deep skillet, melt 1 tablespoon butter over medium heat. Add the leek and cook for 3 minutes, stirring, making sure it doesn’t stick or brown too much. With 1 minute remaining, add the minced garlic and cook until fragrant for the remaining time. Transfer to a small bowl and set aside. Turn off the heat and use the same skillet for the sauce.
• Cook Pasta and Broccoli: Bring a large pot of salted water to a boil, ensuring there is plenty of water as you'll be adding the broccoli later. Add the pasta and cook according to packet instructions, I cook mine for 8 minutes for al dente pasta. With 5 minutes remaining, add the broccoli florets. The water may stop boiling briefly, this is normal. Continue cooking for the remaining time, stirring occasionally to help submerge the broccoli. While the pasta and broccoli cook, make the white sauce.

White Sauce

• Melt Butter: In the same skillet, melt the butter over low-medium heat.
• Make Roux: Once melted, whisk in the flour. Increase the heat to medium-high and cook the mixture for 1 minute as it gently bubbles, whisking continuously.
• Add Milk: Gradually pour in the milk, 1/2 cup at a time, whisking well after each addition. Continue cooking and whisking over medium-high heat until the sauce thickens to a creamy consistency that coats the back of a spoon. This can take several minutes. Do not let the sauce boil.
• Season: Once thickened, reduce the heat to low. Add the ground nutmeg and season with salt and pepper to taste. Whisk well. If needed, continue cooking for another minute or two until the sauce reaches the thick consistency.
• Add Leek and Cheese: Stir through the cooked leek and garlic mixture. Add the parmesan cheese and stir until melted and combined.
• Combine: Drain the pasta and broccoli well. If they have been sitting for a few minutes and started sticking together, briefly run them under hot water to loosen. Add the pasta and broccoli to the sauce and gently stir with a wooden spoon or spatula until evenly coated.
• Serve: Serve immediately with extra parmesan cheese and sliced green onions. Enjoy!