Bring a large pot of water to a boil for the pasta. In a large skillet, heat the EVOO, one turn of the pan, over medium-low. Add the butter and when the foam begins to subside, add the shallots, garlic and sage. Stir until soft, 1-2 minutes. Add the Champagne and simmer until reduced by half, about 4 minutes. Stir in the cream and let the sauce bubble until thickened, 6-8 minutes. Add both cheeses and stir until melted. Remove pan from heat.
Meanwhile, salt the boiling water, add the pasta and cook until al dente. Drain then add the pasta to the sauce. Toss with tongs until coated evenly. Season with pepper.