Take out your kitchen-aid mixer and add the flour, sugar, instant yeast, butter, and salt. Give it a good mix first. As it's mixing the ingredients, pour in little water at a time until the dough forms into a smooth ball.

Touch the dough to see if it's done. If it is too sticky to touch sprinkle some flour as you mix or if the dough turns out too dry and not holding the flour together, add small amounts of water to form a well-mixed smooth dough.

When done, cover the dough lightly with a cloth or cover the bowl with cling wrapping. Set aside for at least 30 minutes or more for it to get the dough to double in size.

Start by adding the oil, curry leaves, ginger, garlic, mustard seeds and the sliced onions on a nonstick pan or pot. Cook it on medium/high heat until the onions start to turn soft and translucent. Stir often to avoid sticking to the pan.

Next, throw in the sliced green leaks, diced tomatoes, turmeric powder, chilli flakes, salt and pepper. Give it a good mix and let it cook further for about 2 more minutes or until the tomatoes soften. Remember to stir often as you cook.

Then lastly add the tuna and the boiled potatoes. Mix well with the rest of the ingredients but careful not to mash them too much. The fish and the potatoes should be broken into pieces rather than mashed. It's alright if few get mushed in the process, it will help hold the fillings together but try to keep them from getting too mushed. It's better if the stuffing is in chunky pieces.

So once you mix the fish and potatoes with the rest of the ingredients, taste test to see if your spices and salt are enough. If needed add more salt and for more spice, you may add chilli powder, black pepper powder, or chilli flakes. Give it a good mix then take off the stove. Set aside for later.

The dough must have doubled in size. Take a golf ball size portion of the dough. Place the dough on the rolling board. Using a roller, roll the dough to a circle shape. It doesn't have to be a perfect round. Then place about 1/2 tbsp or as much fish sambal as needed in the middle of the dough.

Next, we are gonna fold the edges of the rolled dough to make a triangle shape buns. Start by bringing the top two sides of the dough over the stuffing. Pinch the 2 sides together only up to halfway to keep it sealed. Then fold the bottom side of the dough over the stuffing to connect it to the 2 sides you already did.. Now pinch all 3 sides well and it'll look more like a triangle. Turn it over and shape the sides with your hands to form a smooth triangle.

(see picture above to see the step by step instruction to make triangular shape buns)

Line all the fish buns -folded side facing down- on a parchment covered baking sheets. Leave some space around each piece for it to expand. Once done lining them all neatly, cover it loosely with a towel/cloth and keep it aside for about 15-20 min.

NOTE - You may bake without letting it sit aside. However, I do recommend following this simple step. Only because this step will help expand the dough making it slightly puffy, rounder, more of a smooth polished look.

Have a beaten egg ready to brush it off on top of the maalu banis just before the baking. Bake at 320 Fahrenheit (160 Celsius) for 25-30 minutes or until it turns into a golden brown on the top.