2 cups dandelion greens, large stems removed and leaves chopped
2 cups escarole, chopped
4 cups frisée, chopped
2 large shallots, minced
4 cloves garlic, minced
4 cups shiitake mushrooms, stems removed and mushrooms sliced
1 teaspoon sea salt
½ teaspoon freshly ground pepper
2 tablespoon butter
½ cup extra virgin olive oil, divided
¼ cup sherry wine vinegar