Easy Harissa Salmon - Serving Dumplings

Ingredients

• 4 skinless salmon fillets (skinless)
• 1 tsp salt (divided)
• 1 tsp black pepper (divided)
• ½ tsp smoked paprika
• ½ tsp garlic powder
• 1 tbsp olive oil
• 4 tbsp unsalted butter (divided)
• 1 small yellow onion (finely chopped)
• 5 garlic cloves (minced)
• ¼ cup water
• 1 tsp turmeric
• 4 tbsp mild rose harissa (more or less to taste)
• 5 ounces spinach (roughly chopped)
• 2 tbsp lemon juice
• steamed rice (for serving)