Soak your Njahi overnight in Guinness Foreign Extra Stout.
After the soaking time has lapsed, put them to boil until softened then set aside.
In a pan with your heated oil, add your cumin and let it simmer until fragrant. Then, add your chopped red onion, garlic, the finely chopped sage. Let this cook on medium heat for about 5 minutes.
After the onions have softened and the garlic is fragrant, add your pureed tomatoes, your tomato paste and allow it to cook down for about 4 minutes.
Add the boiled Njahi and mix them in. Add all the spices and allow them to simmer for about 10-15 minutes.
5 minutes before removing your stew from the heat, add your finely chopped carrots and green bell pepper.
Once done, serve with a starch of your choice.