Heat the oven to 350 degrees F. Roast all walnuts on a baking sheet until fragrant, 5-10 minutes. Remove and set aside to cool.
In a blender, add red peppers, tomatoes, garlic, nutritional yeast, salt, & lemon juice. Add 3/4 of the walnuts. Stream in olive oil until a very loose consistency is reached.
Boil a large pot of water and cook 1 lb short pasta of choice until al dente. Coat with sauce and top with reserved walnuts.