Add a tablespoon of oil in the pan. Once it is hot, add the onion. Stir for few minutes till it turns light brown.
Add the frozen mixed vegetable. Stir to mix till it is cook.
Add the canned tuna and then mayonnaise. Stir to mix.
Season with salt and black pepper for taste.
Once you are done, transfer into a small bowl for assembling the pie.
In each sliced bread, use the rolling pin to flatten the bread.
Add 1 to 1.5 tablespoon of tuna spread mixture in the sliced bread. Fold it together and use the fork to seal it by pressing the edge of the bread.
Add oil in the pan in medium-low heat to prepare for frying.
Once the oil is hot, add the tuna pie in the pan.
Fry for 30 seconds or till it becomes brown. Flip the opposite and fry that side till it is brown.
Transfer into the plate with a paper towel to drain the oil
Repeat the rest of the tuna pie bread.