Cut turkey breast fillet into strips, quarter the onions lengthways and cut into rings. Fry the meat in a large pan in hot oil until crispy and set aside. In the same pan, fry the onions until translucent, add the meat again and stir in the curry. Pour in the stock and pineapple juice and cook for 5 minutes over a mild heat.
Cut the bananas diagonally into 1/2 cm thick slices. Pour the cream over the meat, bring to the boil and carefully stir in the cornstarch mixed with cold water. Add the pineapple pieces and cook for a few minutes while stirring. Season to taste and add the banana slices just before serving.