1- 9“ refrigerated pie dough - or full diameter and do not flatten out
2 Tbsp unsalted butter
6 portobello mushroom caps - gills remove, halved, sliced crosswise 1/4” thick
1 lb leeks - white and light green only, halved, sliced crosswise 1/4“ thick
1/2 tsp salt
2 garlic cloves - minced
1 tsp minced fresh rosemary
2 oz. Gruyere cheese - shredded (1/2 cup
1 large egg - lightly beaten (optional: brushed on dough for color)
1 Tbsp minced fresh chives (optional)