Classic Chicken Chasseur Cognac - Zest Plate

Ingredients

• 3 russet potatoes
• 4 tablespoons unsalted butter, divided
• 4 tablespoons olive oil
• 3 pounds bone-in chicken pieces
• 2 teaspoons kosher salt
• 0.5 teaspoon ground black pepper
• 1 pound cremini mushrooms, sliced
• 0.25 cup shallots, finely diced
• 1.5 tablespoons garlic, freshly minced
• 0.5 cup cognac or brandy
• 0.5 cup dry white wine
• 3 tablespoons double concentrated tomato paste
• 2 Roma tomatoes, diced
• 1.5 cups chicken stock
• 0.5 cup beef stock
• 0.25 cup sour cream
• 2 tablespoons fresh tarragon, chopped
• 2 tablespoons fresh parsley, chopped