Cow Peas with Sumac, Za' Atar and Beef

1 lb. dry cow peas,
3 T. Za'Atar,
4 T. Sumac,
1 lb. beef shoulder,
2 c. onion,
1 c. green pepper,
1/2c. celery,
1 c. carrots,
8 garlic cloves,
1 Idaho potato,
1 T. sea salt,
1 tsp. black pepper,

about 1 & 1/2 hrs. cooking with 3 qts stew