Perfect Oysters Rockefeller with Spinach and Herbs - Yummy Gusto

Ingredients

• 24 fresh oysters on the half shell
• 4 tablespoons unsalted butter, divided and softened
• 2 shallots, finely minced
• 4 cups fresh baby spinach
• 1/4 cup fresh parsley, chopped
• 2 tablespoons fresh chives, chopped
• 1 tablespoon fresh tarragon, chopped or 1 teaspoon dried tarragon
• 1/3 cup fine breadcrumbs
• 1 tablespoon fresh lemon juice
• 1/4 teaspoon salt
• 1/8 teaspoon black pepper
• Rock salt or coarse salt for baking sheet