Prepare your ingredients ahead of time. Slice mushrooms, chop up parsley, sage and garlic. Get a pot of water boiling for the pasta.
Warm up a large skillet over medium heat. Add the butter and olive oil and continue to heat until the butter is melted. Add the Baby Bella mushrooms and start to cook. Stir occasionally.
Add the pasta to the boiling water. I found that the mushrooms and pasta were done at about the same time.
After the mushrooms have cooked for a few minutes add the fresh garlic. Stir and cook for another minute or two. Add the fresh sage, salt and pepper. Stir.
If the pasta is done add it to the mushrooms along with the parsley. Add a little of the pasta water if needed. You can also add another drizzle of olive oil if you like. Stir to combine everything.