Cook the meat by your method of choice (pressure cooker,braising on stove top or crockpot) with 4 cups water,1/4 of the onion (chop the rest and reserve for next steps), 2 whole peeled garlic cloves and salt.
Cook until meat is tender.
Take the meat out of cooking pot and sieve the stock, reserving 2 cups.
Cook the rest of the ingredients, except cornstarch, over medium heat until it boils.
Dissolve cornstarch in 1/4 water, add to previous ingredients and stir until it mixes in.
Add the meat, season with salt and pepper, cover the pot, and simmer for 10 more minutes.