Butterfly the chicken breast and then flatten it with a meat mallet to an even thickness of around 1-1½cm (½").
Mix together the onion salt, garlic granules, and smoked paprika with the cooking oil, then coat the chicken well and set it aside.
Cut the red onion in half, then peel it and slice it into very thin half-moon shapes.
De-seed the chilli for the dressing and dice it as finely as you can, then place it into a jar with the remaining dressing ingredients, mix and set aside.
Cut the bread into 1cm (½") cubes (I cut the crusts off and eat them as I cook because I'm greedy).
Roughly chop the coriander.
Cut the cheeks off the mango, slice the flesh into long strips, taking care not to cut through the skin. Finally, use a spoon to pop out the mango strips.
Heat a frying pan (not nonstick) over a high heat, and when it is hot, add the chicken breast and cook for 3-4 minutes on each side, then remove and allow to rest. Ensure that the internal temperature of the chicken reaches 73°C or 165°F!
Add the olive oil to the pan that the chicken was cooked in and toast off the diced bread to form some crispy croutons.
Heat a griddle pan over a high heat and sear the mango on both sides to get some nice griddle marks, then remove and place in a bowl with the chopped coriander and toss to coat.
Cut the Romaine lettuce in half lengthways and add them cut side down to the griddle pan to get some nice griddle marks, then remove and roughly chop and add to the bowl with the mango.
Slice the chicken into strips around 5mm (¼") thick and add them to the lettuce and mango mix.
Throw in the red onion, season with the dressing and toss to coat.
Serve in bowls adding the croutons to finish the dish.