Boil 4 potatoes in water along with some salt and drain them once they become tender and soft.
Mash them and let it cool down. In a pan, add a pinch of chopped garlic, grated ginger and some finely chopped onions in olive oil and saute for 2 minutes. Then add salt and pepper along with the chopped beans and carrots. Turn off the flame and keep it aside.
Then mix 1 cup milk with some wheat flour to achieve a thick sauce-like consistency and season it with some salt and pepper.
Grease the baking tray with some butter and add the vegetables and the potatoes in it. Pour the white sauce on top and bake it for 10-12 minutes in the oven at 200 degrees C. If cooked, garnish it with some grated cheese and paprika.