Mussels and Shrimp in Garlic Tomato Sauce

Ingredients

• 1 tbsp olive oil
• 1 tbsp unsalted butter
• 14 ounces shrimp (peeled and deveined)
• 1 yellow onion
• 4 garlic cloves
• 1 celery stalk
• 1 tbsp tomato paste
• 1 tsp salt (divided)
• 1 tsp black pepper (divided)
• 1 tsp smoked paprika (divided)
• 1 tsp sugar
• ½ tsp chili flakes
• 1 bay leaf
• 1 can (14.5 oz/400 ml) whole peeled tomatoes
• 2.2 pounds mussels
• 4 thyme sprigs
• ½ cup chicken broth
• parsley (for serving)