Boil pasta according to package instructions, add a little olive oil to the pasta water to keep the pasta from sticking..drain and set aside
Remove the stems from the fennel bulb, and cut the Fennel into slices. Set aside
Heat 2 tablespoons of oil in a large saucepan over medium heat. Add onion, and cook until soft, about 2 minutes
Stir in Fennel and cook for another 2 minutes, stirring constantly.
Add the garlic and cook until fragrant, about 30 seconds
Move the vegetables to one side of the saucepan.
Add the remaining 1 tablespoon of the oil followed by the flour, cook until the flour is slightly golden but not brown.
Stir in nutritional yeast flakes, salt, water and vegan milk.
Stir constantly until the sauce is smooth and creamy.
Add the pasta and stir to coat.
Serve immediately