Easy Fish Roll Recipe. Ingredients: For the pastry/dough * 500 grams of Flour * 1 teaspoon baking powder * 1 tablespoonful of sugar * 1 large raw egg * 100 grams of margarine/butter * 1/2 cup water (or enough to get a smooth, firm dough) * Lemon Zest (optional) * 1/2 teaspoon salt For the filling: * Fresh mackerel fish * Vegetable oil for frying * 1/4 teaspoon black pepper(optional) * 1/2 teaspoon thyme * 1 teaspoon minced garlic * Seasoning Powder * 1 Medium-sized Onion * Red Bell Pepper * Gree