Add butter to a large pot over medium heat. Allow to melt, but not brown. Add sliced baby bella mushrooms, minced shallot, and minced garlic to pot. Cook and stir for 2 minutes until aromatic.

Sprinkle dried dill, dried thyme, and paprika into pot and stir. Whisk in Worcestershire sauce, white wine, and beef broth. Taste and season with salt and pepper. Bring pot to a boil, pour in couscous, and cover pot with a lid. Turn heat down to medium and simmer for 20 minutes.

Check couscous for doneness. It should be soft and chewy. Add more time if needed. Once couscous is done, remove pot from heat and stir in half and half. Serve with sour cream and crusty bread.