Ingredients

• 2 tablespoons olive oil , divided
• ½ onion , chopped
• 1 cup chopped fresh mushrooms
• 2 teaspoons minced garlic , divided
• salt and ground black pepper to taste
• 1 cup baby spinach
• 1 tablespoon all-purpose flour , or as needed
• 2 sheetss frozen puff pastry , thawed
• 1 , 1 ½-pound
• 0.5 teaspoons smoked paprika , or more to taste
• 1 egg , beaten

Instructions

1. 1 Gather all ingredients.
2. 2 Heat 1 tablespoon oil in a large skillet over medium heat. Add onion; cook and stir until translucent, about 5 minutes. Add mushrooms and 1 teaspoon garlic; cook and stir until mushrooms are soft, about 5 minutes. Season with salt and black pepper. Transfer onion and mushroom mixture to a small bowl.
3. 3 Heat remaining 1 tablespoon oil in the same skillet. Add remaining 1 teaspoon garlic; cook and stir until fragrant, about 30 seconds. Add spinach; cook and stir until wilted, 3 to 5 minutes. Season with salt and black pepper. Transfer to another bowl.
4. 4 Preheat oven to 350 degrees F (175 degrees C). Line a glass baking dish with parchment paper.
5. 5 Dust work surface with flour. Lay 1 puff pastry sheet out on work surface; spread onion and mushroom mixture evenly across pastry, leaving a 1/2-inch border. Center salmon on top; sprinkle paprika over salmon and top with wilted spinach.
6. 6 Cover with second puff pastry sheet. Fold over and crimp edges to seal. Brush top with beaten egg. Transfer to prepared baking dish.
7. 7 Bake in the preheated oven until pastry is golden, 40 to 45 minutes. Let cool briefly, then slice into 4 portions.
8. 8 To make the sauce: Whisk mayonnaise, lemon juice, Dijon mustard, and dill together in a small bowl.
9. 9 Spoon sauce onto 4 plates and place a piece of salmon en croûte on each.

Nutrition per serving