Salmon Satay Burgers With Onion Relish

For the relish: 

• 1 cucumber, peeled, diced 
• 1 small red onion, sliced 
• 3 tbsp. rice wine vinegar 
• 1 tsp. coconut sugar 
• ¼ tsp. salt 

For the burgers: 

• 1 lb. (450g) salmon, finely chopped 
• 2 tbsp. shallot, finely chopped 
• 1 jalapeño pepper, seeds removed, diced 
• 1 stalk lemongrass, tender part finely chopped 
• 2 tbsp. fresh cilantro, chopped 
• 2 tsp. ground cumin 
• 1 tsp. ground turmeric 
• 1 egg, beaten 
• 5 tbsp. panko breadcrumbs
• ½ tsp. salt
• ½ tsp. black pepper
• 1 tbsp. coconut oil 
• 4 burger buns