Andrew Zimmern Cooks: Shrimp Étouffée

Ingredients

• 2 tablespoons vegetable oil
• Reserved shells from 2 pounds large shrimp (see below)
• 1 small onion, chopped
• 1 medium carrot, chopped
• 2 celery ribs, chopped
• 3 cups chicken stock
• 1 1/2 sticks unsalted butter
• 1 medium onion, diced
• 8 garlic cloves, thinly sliced
• 3 bay leaves
• 1 1/2 teaspoons ground celery seed
• 3 tablespoons thyme leaves, finely chopped
• 1 cup tomato paste
• Freshly ground black pepper
• 2 celery ribs, thinly sliced
• 6 large scallions, thinly sliced
• 2 tablespoons Crystal hot sauce, plus more for serving
• 2 pounds large shrimp, shelled and deveined, shells reserved
• 1 tablespoon fresh lemon juice
• Salt
• 2 tablespoons parsley, chopped
• Steamed rice and lemon wedges, for serving