1. Saute onions in vegetable oil until soft.
2. Mix in flour and cook for about 5 more minutes (should be slightly runnier than a paste. if too thick, add more oil.)
3. Combine rest of dry ingredients in bowl.
4. Add tomato sauce to pan with onions and flour.
5. Add water and dry ingredients, whisk until blended.
6. Cook for about 5 more minutes.
7. Remove from heat and set aside