Fish pie, a super delicious English recipe - Yummy Expert

Ingredients

• 600 g salmon
• 1 tbsp salt
• 1 tbsp black pepper
• 1 tbsp boya
• olive oil
• 6 potatoes
• water
• 30 g butter
• 2 tbsp flour
• 200/250 ml milk
• 1/2 juice of lemon
• 100 g cheddar cheese
• 1 tbsp mustard
• parsley
• spinach