1. Cook the pasta according to the instructions of each manufacturer.
2. Set aside the pasta and save 1 cup of the cooking water.
3. In the blender, add the walnuts, garlic, nutritional yeast, 3 tablespoons of olive oil, and a little salt to taste.
4. Blend well until you form a homogeneous sauce. Set it aside.
5. Separately, peel the pear and cut it into small cubes.
6. Brown the pear in a pan over medium heat with a little olive oil.
7. When the pear is golden, add the pasta, the pesto, and the cup of cooking water that was previously reserved.
8. Stir until the pasta is coated with the sauce.