To cook meat, place meat in a pot of water on high heat, let it boil, and remove any floating scum and fat. Let it boil for a couple more minutes.
Remove meat from the pot, and wash it. Set aside.
Wash the green beans, remove the tips, and chop to 3 cm-long pieces.
In a frying pan heat vegetable oil, and fry the beans and saute lightly for 4-5 minutes.
In your slow cooker place the meat, a whole onion, the slightly cooked beans, salt, pepper, 1 bay leaf, and any spices desired (I add Baharat). And let it cook on high for 4-4.5 hours. (or on low for 8 hours).
When the beans and the meat are almost done. In a frying pan heat some vegetable oil and slightly fry the minced garlic, and chopped onion. Add the flour, 3-4 tablespoons tomato sauce, and broth (from the meat), mix well and let it boil with stirring. (You can add a bit of vinegar or sugar for taste)
Add the mixture to the crockpot, and let it cook for 20 more minutes.