Place the mango, chayote, bell pepper, parsley, mint, lime juice, salt, pepper and cayenne in a mixing bowl. Gently toss the ingredients until they are evenly distributed; set aside.
Melt the ghee in a non-stick skillet set over medium heat; while the fat is heating up, pat the fish fillets really dry, sprinkle them lightly with salt and pepper on both sides and then place them in the hot pan. Make sure you leave ample room for air to circulate around the fillets. If your pan isn't large enough to accommodate all of your fillets, cook them 2 at a time.
Cook the fillets for about one minute per side, or until a lightly golden crust forms and the fish turns opaque.
Divide the reserved salad between 4 plates, top with a fillet of sole and garnish with a handful of microgreens.
Serve immediately.
Notes
You can make the salad up to a day in advance and keep it in the fridge until ready to serve.