King Oyster Scallop Cioppino

Name: King Oyster Scallop Cioppino
Cuisine: Mediterranean
Ingredients: 1/2 pound king oyster mushrooms (stalks cut into 1 1/2" thick rounds); 1 tablespoon vegan butter; 1 tablespoon olive oil; 1/4 cup celery (thin sliced); 1/4 cup yellow onion (small diced); 4 cloves garlic (thin sliced); 1 - 15- ounce can garbanzo beans (rinsed and drained); 4 Roma tomatoes (diced); 1 1/2 cups vegetable broth; 1 teaspoon Old Bay seasoning; 1/4 cup lemon juice; salt (to taste); ground black pepper (to taste); 2 tablespoons fresh parsley (chopped and divided)