In a frying pan, heat the coconut oil over medium heat.
Add the chicken tenders, onion, and bell pepper. Cook until the chicken is lightly browned and 165 degrees internal temperature.
Remove chicken mixture to a dish and set aside.
In a small cup, stir together the juice and corn starch until no lumps remain. Set aside.
Return the skillet to the heat without wiping or rinsing. Add water and bouillon base and bring to a boil over medium heat. When it comes to a boil stir in the corn starch and juice mixture. Return to the heat and boil for 1 minute. Sauce will thicken. (NOTE: If you don't have the bouillon base, you can use 1 cup of chicken stock.)
Add the mango and pineapple with juice to the boiling water mixture and simmer for 3 minutes until fruit is thoroughly heated.
Return the chicken and vegetables to the pan. Stir to coat with sauce.
Serve Pineapple Mango Chicken over rice.