Place mayonnaise, sour cream, lime juice and chili powder in a small bowl, whisk until the ingredients are fully combined. Store in an airtight container until ready to use.
Heat oil in a large heavy based pan. Add onion slices and a pinch of salt, fry for 5 minutes until translucent, lower heat and fry for 15 minutes until caramelized.
Spray barbecue grill with oil. Heat on medium high heat. Cook patties for 5 minutes each side until cooked through and top with cheddar cheese. Toast burger bun on grill.
To assemble the burgers, spread a few tablespoons of avocado on the bottom bun and place burger on top. Cover with carmelized onion, chipotle mayonnaise and rocket leaves. Serve immediately.
Lusine Sesame Seed Burger Buns 
Avocado Hass Mexico 
Rocket UAE 
President Slices Burger Cheddar 
Onion Brown Spain 
Nezo Fine Sea Salt 
Al Arabi Vegetable Oil 
American Garden US Mayonnaise 
Lime India 
Bayara Paprika 
Shan Red Chili Powder 
