Bring a large pan of water to boil. Add the asparagus and boil asparagus until tender, about 5 minutes. Using a slotted spoon, remove the asparagus from the water and and place into a blender. Keep the pan of water on the cooktop over low heat. This water will be used in the pesto and to cook the pasta.

Add 1/4 cup of the asparagus water, garlic cloves, salt and vinegar to the blender. Puree until smooth. With the food processor still on, slowly add the olive oil into the mixture. Continue to blitz until thickened. Add the parmesan and continue to blend. Turn off the food processor and stir in the black pepper and red pepper flakes. Set aside.

Bring the asparagus water to a boil and add the fusilli. Cook until tender, about 10 to 12 minutes. Strain the pasta from the water and place into a serving bowl.

Add the asparagus pesto, fresh lemon juice and basil to the pasta. Toss to combine and salt to taste, serve warm.