Heat a large skillet over medium heat and add olive oil. Once shimmering, add minced garlic and cook for about 30 seconds until fragrant, with a light golden hue and a fragrant aroma filling the kitchen.
Add the uncooked spaghetti to the skillet, stirring to coat the noodles with the garlic and oil. Pour in the broth, then sprinkle with salt, black pepper, and red pepper flakes if using. Raise the heat to high and bring the mixture to a boil.
Reduce the heat to medium and let everything simmer gently, stirring occasionally, for about 10 minutes. During this time, the pasta will soften and absorb the flavorful broth, and you will notice the liquid reducing and thickening slightly, with a bubbling sound and a pleasant aroma of garlic and cheese.
Once the pasta is tender and most of the liquid has been absorbed, remove the skillet from heat. Stir in the grated Parmesan cheese until melted and smoothly incorporated, creating a rich, creamy sauce that coats the noodles evenly.
Taste and adjust seasonings if needed, adding more salt or pepper to your preference. The dish should look glossy, with a cheesy sheen and tender noodles with some garlic bits visible on top.
Serve the garlic Parmesan pasta hot, garnished with extra Parmesan or herbs if desired. The dish offers a creamy, flavorful mouthfeel with the pasta perfectly cooked and coated in cheesy garlic goodness, ready to enjoy.
