In a large pot, bring salted water to a boil and cook the fettuccine according to package instructions. Drain and set aside, reserving ½ cup of pasta water.
In another pot, add the chopped cauliflower and cover with vegetable broth. Bring to a boil and simmer until the cauliflower is tender, about 10-12 minutes.
Drain the cauliflower and add it to a blender along with the olive oil, garlic, almond milk, nutritional yeast, lemon juice, onion powder, and a pinch of salt and pepper. Blend until the mixture is completely smooth and creamy, adding reserved pasta water a little at a time if needed for desired consistency.
Taste and adjust seasoning, adding more salt, pepper, or lemon juice as needed.
In a large bowl, combine the cooked fettuccine with the creamy cauliflower sauce, tossing to ensure all the pasta is well coated.
Serve immediately, garnished with freshly chopped parsley for a pop of color.
Notes
Adjust seasoning to taste and use any pasta of your choice.