Heat the olive oil in a large deep frying pan on medium-high heat. Add the garlic and cook to soften, but not quite brown.
Add the spinach and sauté with the garlic until wilted. Season with salt and pepper, remove from heat and set aside.
Cook the pasta according to the package instructions. Reserve a cup of the pasta water before draining. Drain, and set aside.
Add the spinach and garlic mixture to a food processor or blender with the cheese and half of the pasta water. Puree until it forms a sauce (adding more pasta water if needed).
Add the sauce back into the pan to combine and heat through, again adding more pasta water if needed.
Once heated through, taste and season with more salt and pepper if necessary. Serve sprinkled with extra grated cheese.
Work fast with the garlic. Garlic burns easily, especially when chopped or sliced. If you’re worried it may burn, keep a little water handy and add a tablespoon or two before adding the spinach to the pan.
To puree the sauce, I use a food processor, but a blender would also work if you add the pasta water in before blending.
I use fresh spinach, but frozen would work too if it’s thawed and squeezed of excess water.