Place a baker in oven and preheat to 450°F for 10 min. Meanwhile, in a bowl, combine mushrooms, lemon juice, parsley, sherry, chili flakes, 1/4 tsp. piment d'Espelette, broth and salt and toss to coat evenly.
Put olive oil and garlic in preheated baker and bake for 1 min. Add mushroom mixture and bake, stirring after 8 min., until mushrooms are tender and cooked through, about 15 min.
Garnish with piment d'Espelette and serve immediately with crusty bread.
