In a medium-sized pot or dutch oven over medium heat, add the olive oil and onion and cook for 3-4 minutes, stirring occasionally, until semi translucent.
Add the garlic and cook for 2-3 minutes.
Transfer onion and garlic to blender. Add the soaked cashews, red pepper, nutritional yeast, tomato paste, cornstarch, salt, paprika, ground mustard, turmeric, and vegetable broth, and blend until smooth.
Transfer sauce back into pot and cook until thickened, about 5 minutes.
Add pasta to the pot and stir until sauce is evenly distributed.