Cook pasta according to package directions. 2-3 minutes before pasta is done, add mushrooms and peas to blanch them. Drain all and set aside. Add a small drizzle of olive oil and stir to prevent pasta from sticking.
Add cottage cheese, milk, cornstarch, paprika, garlic powder, and salt to a blender or food processor and blend until smooth and creamy, about 30 seconds.
Pour the sauce into a pot and cook over medium heat until it starts to thicken, stirring very frequently. Add pasta, butter, and black pepper, stir, and cook over low heat for 1-2 minutes until thickened and the sauce coats all the pasta.
Remove from heat, stir in cheddar cheese, and keep stirring for 30 seconds to 1 minute until cheese is fully incorporated. Adjust seasoning if necessary and serve.
