Add butter and garlic to deep pan. Sauté 1 minute over medium heat. Add mushrooms, salt, and pepper. Continue to sauté until mushrooms have softened, browned, and moisture has evaporated.
Add dry fettuccini and broth. Stir to combine and cover. Turn heat up to medium-high and allow broth to boil. Stir pasta, replace lid, and turn heat down to medium-low. Simmer 12-14 minutes, stirring occasionally (there will be a little liquid left). Remove from heat.
Add blended cottage cheese and stir to combine. Add parmesan and stir until melted.