A great way to serve portabellas is to stuff them. Truth be told, the cap of a portabella, though large, is not very deep. What you really end up with is something more akin to a portabella pizza.
Prep the caps:
Stem the mushrooms and scrape the gills out of the caps with a teaspoon. Rub the caps generously with olive oil on both sides, season with salt and pepper, and either sauté, grill or broil them until tender, about 5 minutes per side.
Make the filling and broil:
Heat 1-1/2 Tbs. olive oil in a medium skillet over medium-high heat. Add the pancetta and fry until lightly golden. Add the onion and cook, stirring, until the onion is soft and lightly browned. Add the sage and the Parmigiano; season amply with pepper. Divide the filling between the two prepared portabella caps. Sprinkle each with a little more cheese; broil briefly to melt the cheese.
Photo: Judi Rutz