Cook the pasta in a large pot of water according to package instructions in salted water; remove 2 minutes before recommended cooking time. Reserve some pasta water.
While pasta is cooking, heat a large skillet over medium heat for a few minutes; add olive oil. Once heated, add shallots and garlic; saute until lightly golden.
Add sauteed mushrooms, chopped sage, and ½ teaspoon sea salt. Saute for approximately 5 minutes, stirring occasionally, until edges of mushrooms are browning.