Crab soup with ginger is a traditional dish of the Lamu archipelago.
The local population, especially on the island of Pate, usually eat this dish accompanied by coconut rice or chapati.
Here is the original recipe reworked by malindikenya. net

READ THE FOLLOWING RECIPE

Ingredients for 4 people:

200 days of crab flesh
10 tomatoes
3 cloves of garlic
a grating ginger
two ladles of fish broth (you can also boil the body of clean shrimp or add vegetables)
a bunch of coriander (it's also fine parsley)
1 green pilipil (or half a teaspoon of paprika)
pepper and salt
two tablespoons of olive oil
a glass of white wine (for the non-Muslim version)
five or six of ground mustard seeds
half a teaspoon of cumin powder
two cups of water

Procedure:

In a pan, fry the tomatoes with garlic and a tablespoon of oil, after adding to the fried a first light grated ginger, salt and chilli pepper and two fingers of wine.
When the sauce is compact, add what remains of the glass of wine and after two minutes the crab flesh.
Let it heat slowly for five minutes, adding the stock and water from time to time. Two more minutes after adding mustard and caraway. Turn off the heat, add to the mixture the other tablespoon of olive oil, another grated ginger and a dusting of coriander or parsley. 
Serve in the table with chapati or bread croutons.

Translated with www.DeepL.com/Translator