Kawal

Step 1: A word of caution first: senna plants are traditionally known as laxatives, so kawal is used in small amounts as a seasoning. It is not suitable for pregnant or breastfeeding people or babies, and anyone taking medication should check with a doctor. Never eat the seeds or pods, and if you are not completely sure of the plant, do not forage it.

Step 2: Strip the 2 ¼ lb young wild senna leaves from the stems, discarding any yellow or damaged ones. Rinse quickly in cold water, spread on a clean cloth and let them dry in the shade for about 1 hour, until no water clings to them.

Step 3: Pound the leaves in a mortar in batches for 10–15 minutes each, until they form a smooth, dark green, sticky pulp. Add a few drops of 2 tbsp water only if the pulp is too dry to come together. A food processor also works.

Step 4: Scrub a clay pot or a 1 litre glass jar with hot soapy water, rinse with boiling water and let it dry completely.

Step 5: Line the pot with some of the 10 clean sorghum or maize leaves, pack in the pulp firmly to press out air, cover the surface with more leaves and put the lid on loosely so gas can escape. Keep it in a cool, dark, shaded place at 20–77°F.

Step 6: Every 3 days, tip the paste out with clean hands onto a clean board, knead or re-pound it for 5 minutes, and pack it back under fresh leaves. Continue for 10–14 days. It is normal for the paste to darken to olive-black, turn sticky, feel slightly warm and smell strongly of ammonia and savoury cheese. Fuzzy mould in blue, green, black or pink, a wet, slimy texture or a sewage smell mean it has spoiled: throw it away.

Step 7: When the paste is dark, sticky and strongly savoury, roll it into balls about 3 cm across and flatten them slightly. Dry them in strong sun on a clean tray covered with fine mesh for 3–5 days, bringing them in at night, or in a 122°F oven or dehydrator for about 10 hours, until they are completely hard and snap cleanly with no damp centre.

Step 8: Store the dried balls in an airtight jar in a cool, dry place for up to a year; discard any that soften, smell damp or show mould. To use, grind or crumble 1–2 teaspoons into a stew for four, such as onions, okra and tomato, and simmer for at least 20 minutes so the pungency mellows.