This recipe is totally not from Nigeria. The beef-spinach stew in the Nothern part of Nigeria; precooked mashed pumpkin is use as the thickening agent. In addition some spices (like ground fresh or dry pepper, ginger and cloves) and vegetable oil are added to the soup. This soup is served with mashed rice, Tuwo or pounded yam
I just have to make some corrections to this dish and to the comments above: First, this is not Efo Riro because the cornstartch was meant to act like the egusi. Second, the ginger ale should never have been put into this stew. I don't know why it was suggested, but it is not needed. Also who uses soda in their stews? That is rather disgusting. Third, this recipe is not even close to the original because the texures and taste are too different. Also you are supposed to grind the tomatos and onions together into a somewhat puree. Fourth, this should just be called a beef-spinach stew(not Nigerian) because it is totally dissimilar to real Nigerian stews.
This adaptation was a good idea but unfortunately, the results are a big let-down. This tastes nothing like the original Efo-Riro (Yoruba name for this recipe). Sometimes it's best to stay true to the original rather than try to remake it.
I made this in a slow cooker and simmered it all day, then served it with couscous. Delicious-the kids loved it too!