Bouillabaisse burgers with tomato-fennel relish and saffron mayonnaise Recipe | Food Network UK

Ingredients

• For the tomato-fennel relish
• 65g seeded and finely chopped firm ripe plum or vine-ripened tomatoes
• 40g finely chopped fennel
• 3 tbsps finely chopped sweet onion
• 1/2 tsp grated fresh lemon zest
• 15ml fresh lemon juice
• 3/4 tsp fresh thyme leaves
• 15ml garlic-flavored olive oil
• 1/8 tsp rock salt
• 1/8 tsp freshly ground black pepper
• For the saffron mayonnaise
• 1/4 tsp saffron threads
• 185ml good-quality mayonnaise
• Pinch rock salt
• Pinch freshly ground black pepper
• For the burgers
• 850g skinless, boneless red snapper fillets (or any other firm-textured white lean fish), coarsely ground (in small batches) in a food processor or chopped into about 0.5cm pieces by hand
• 350g peeled and deveined large raw prawns, cut into about 0.5cm pieces
• 5 egg whites
• 1 1/4 tsps chopped fresh thyme leaves
• 1 tsp rock salt
• 1/2 tsp freshly ground black pepper
• 100 to 120g panko (japanese bread crumbs), or as needed
• Rapeseed oil, for brushing on the grill rack
• 12 slices, about 1 to 1.5cm thick, french bread, cut from center of 1 loaf or 2 loaves
• Garlic-flavored olive oil, for brushing on both sides of bread slices