Hairy Bikers Salmon En Croute Recipe 🐟

Ingredients

• 1 tbsp olive oil
• 1 onion, finely chopped
• 2 garlic cloves, crushed
• 250g chestnut mushrooms, sliced
• 200g baby spinach
• Salt and black pepper
• 50g butter
• 50g plain flour
• 300ml milk
• 2 tsp Dijon mustard
• 2 tbsp chopped fresh dill
• 500g puff pastry
• 1 egg, beaten
• 4 salmon fillets, skinless and boneless
• Sesame seeds, for sprinkling