Sea Trout Baked with Thyme and Rarebit Mussels

Ingredients

• 1 tbsp butter
• 1 heaped spoon of flour
• 1 tsp mustard
• Bottle of beer (I used a 300ml Scottish IPA)
• ½ tsp cayenne pepper
• ½ cup mature cheddar, grated
• 1 egg yolk
• 4 hunks of bread
• Side of trout or salmon
• 1 spoon oil (I used rapeseed)
• 2 lemons, sliced into rounds
• Handful of thyme
• Salt and pepper