Preheat the oven to 180°C and line a baking tray with non-stick baking parchment.
Add the red onion and chilli to a food processor and pulse until coarsely chopped. Add to a mixing bowl.
Add the tomatoes, red pepper and mango to a food processor and pulse again until coarse (this won't take as long as the onion so be careful not to over chop!). Add to the mixing bowl.
To the chopped vegetables, add the garlic, tomato puree, lime juice and sweetener. Stir to combine and season with salt and pepper. Leave to one side.
Add the chicken breast, breadcrumbs, soy sauce, garlic granules, onion powder and paprika to a food processor and pulse until smooth. Add to a bowl along with 5 tbsp of the mango salsa. Mix until combined.
Divide the mixture into 6 and shape into 6 patties. Place onto the baking tray and cook for 25 minutes until cooked through.
While the burgers are cooking, combine the mayonnaise, Sriracha and lime juice in a small bowl and mix. Spread onto the top and bottom halves of each roll. Top the bottom half of the roll with tomatoes, onion and mixed leaves.
Add a little of the mango salsa and finish with the burger patties and place the top of the roll on top and serve with accompaniment of your choice.