Steps
1. In a skillet, melt the margarine over medium heat.
2. Add the diced chicken breast, season with salt and pepper, and cook until browned (about 5-7 minutes).
3. Stir in the corn and cook for another 3-4 minutes.
4. Add the ketchup and flaked mackerel, mixing well to combine.
5. Cook for an additional 2-3 minutes until everything is heated through.
6. Serve hot, garnished with chopped parsley if desired.