Fry the onions in preheated oil, turning them gently until they turn yellow. Add the garlic and stir for a minute.
Add the meat cubes and water, stir and simmer on low heat for 10 minutes.
Whisk the Corn starch in the 1/4 cup of water, and pour it on the Yogurt.
Add the Tahini, salt and white pepper, and blend well.
Slowly pour the yogurt mixture in the cooking meat, stirring continuously, in one direction, until boiling point.
Remove the Laban Oummo from the heat, and pour it into a deep serving plate.
Sprinkle with dry mint, and the pine kernels.
Serve with Lebanese Vermicelli Rice on the side.