Blend onion, ginger, garlic in blender/food processor. Heat oil on medium high. Saute onion paste till it gets very lightly browned. At this point you can add the tomatoes and continue cooking till tomato loses its shape and starts blending in with the paste. Add spices and saute for 1 minute. Add ground meat and brown. Once meat is browned add a little water and simmer covered until cooked through. Add garam masala after you have removed the pan from the stove.
Garam Masala is a common Indian spice mix. It is available commercially and ingredients vary or you can make your own.