Bake Gorton's fish fillets according to instructions on the packaging.
To make the salsa, peel mangos, cucumber, and onions. Dice all fruit and vegetables and place in a medium bowl. Add fresh lime juice and salt to taste as it will bring out the flavors. Toss salsa; set aside.
Toast corn tortillas over stove top burner flame. They can also be warmed in the microwave if desired. Heat refried beans according to package directions.
Assemble tacos with cooked fish fillets, mango salsa, and feta cheese.