Cook ravioli according to package directions, leaving them al dente.
Melt butter over medium heat. If using dried sage, add it now. Add mushrooms and saute until mushrooms are cooked down and butter is brown, but not burned. If the mushrooms have soaked up all the butter, add in another 1-2 tablespoons of butter and cook until browned.
Drain ravioli and reserve a bit of the starchy cooking water.
Toss in cooked ravioli and fresh sage. Add 1 T- 1/4 c cooking water. Turn pasta, mushrooms and sauce onto serving plates and top each with a couple of grinds of black pepper and a pinch of sel gris.