Place chicken, carrot, egg white, cornflour, sugar, ginger and black pepper in a food processor. Pulse until the chicken is well minced. Cut each slice of bread into 4 triangles. Spread the tops and sides of each triangle with the chicken mixture.
Melt half of the margarine in a nonstick frypan over medium heat. Place half of the triangles, spread side down, in the frypan. Cook until golden brown, about 4 minutes. Flip with a spatula and cook until the other side is brown, about 2 minutes. Transfer to a serving platter and keep warm. Repeat process with the other half of the triangles and margarine. Serve with soy sauce for dipping.