Bring a pot of salty water to boil and cook the fregola until soft and chewy, 10-12 minutes.2In the meantime, heat a little olive oil in a skillet over medium heat and add the mushrooms. Cook until they begin to release their liquid, then add the garlic, rosemary, and a good pinch of salt. Let the moisture cook away, then let the mushrooms gently brown and toss in four of the sliced sage leaves just as they finish.3Drain the fregola well, then return it to the pot and add the mushrooms. Toss and moisten with olive oil as desired. Top with freshly ground pepper and the last sage leaf.