Now, add mashed potatoes in this veggie mixture and sprinkle salt and white pepper powder in it. Mix all the ingredients well and take portions of the mixture. Shape them into 4 round patties. Meanwhile, add butter in a non-stick pan and heat it over medium flame. Add the prepared patties and fry them for 30 seconds on both sides or until lightly browned.
Bring the flame to low and and then, add a cheese slice on top of the patties. Cover with a lid and cook for another 30 seconds or until the cheese starts to melt. Then, slice the burger buns into halves and warm them slightly. Spread butter on one half of the burger buns.
Now, add some cabbage on it, and top it up with tomato slices, cucumber and onion slice. Place the cooked burger patty with the cheese on top. Sprinkle a bit of pepper powder and top up with some sauce of your choice. You can also use different dressings of your choice. Cover with the other half of the bun and serve the scrumptious burger with fries and potato wedges.