Start by cutting the mango into cubes and add it into a blender. Add the onion, garlic cloves, red chili, olive oil, chicken seasoning blend, and lemon juice and blend everything nicely.
Take a Ziploc food-grade plastic bag, add the chicken breasts and pour in the mango spice marinade. Close the zip bag and massage the chicken breast, so that the chicken pieces become nicely coated with the spicy mango mixture. After that, let the chicken rest in the refrigerator for an hour.
Brush the grill pan with some coconut oil and preheat it before placing the marinated chicken breasts on it. Apply the remaining mango blend on the chicken pieces by using a brush. However, don't forget to flip the pieces occasionally and keep doing it until the chicken is fully cooked. When the chicken is done, and the centers are cooked through, remove them from the grill pan and let them rest for a few minutes.
Chop the cherry tomatoes and bell pepper. Put the washed lettuce, spinach, tomatoes, and bell pepper in a bowl and transfer the grilled chicken on top of the salad.