Make the white sauce the same as you do any bechemel
Brown the ground beef, breaking up any clumps and set aside
In the same pan fry the onion until slightly golden
Add garlic and ginger paste and cook for 1-2 min
Add spices and cook for a further 1-2 min
Add diced tomato and cook until a paste forms
Return meat to pan and mix well. Fry until dry/roasted
Slice the bread to desired thickness and top with sauce, meat, cheese, fresh corriander
Bake for 10 min at 375F and serve hot