New England Style Oyster Mushroom Chowder

Name: New England Style Oyster Mushroom Chowder
Ingredients: 4 tbsp Cal & Gary's butter, divided; 1 tbsp minced garlic; 3/4 lb oyster mushrooms, roughly chopped; 1/2 tsp salt; 1 yellow onion, 1/4 in dice; 2 stalks celery, 1/4 in dice; 1 lb Yukon gold potato, diced 1/3 in thick; 2 tsp fresh picked thyme; 2 tsp Old Bay seasoning; 3 bay leaves; 1/2 cup instant potato flakes; 2 cups mushroom or vegetable stock; 2 cups 2% milk; 1 cup whipping cream; salt and freshly cracked black pepper, to taste; chopped fresh parsley, for garnish