Drain half of the tomato sauce from the mackerel and place in a medium sauce pan. Then add the onions, curry powder and let it simmer for about 10-15 minutes until almost all the liquid has evaporated, add parsley. Stir and simmer for about 2 more minutes. Set aside and let it cool.

Using a stand mixer or by hand, mix the flour, baking powder, salt, then add margarine, mix well until the ingredients have been fully incorporated.
Turn the dough out onto a lightly floured surface. Knead it just until all the flour is incorporated and the dough is smooth

Heat up a large skillet or cast iron with oil up to ½ inch- medium-high heat (375) until hot but not smoking.
Scoop up the batter with a spoon preferably and fry in batches, turning once, until golden brown, about 5 minutes. Do not overcrowd the pan (it will absorb excess oil, resulting in a soggy fish pies)
Using a slotted spoon, remove the fish pie and place them on paper towels.
Serve warm