A recipe for ugali
upishi = recipe/cookery
wa = of
ugali = ugali (awkwardly translated as "stiff porridge")
By the way, Ugali is a kind of posho here in East Africa. It is relatively maroon in colour.
And practically speaking, posho is a form of stiff porridge. So ya, I think I understand why Duolingo would go with this translation.
stiff porridge -- (usually uncountable, plural stiff porridges) porridge made with a greater proportion of meal or flour so as to achieve a thicker consistency, similar to dough (common in many African cuisines). https://en.wiktionary.org/wiki/stiff_porridge. This phrase was used by F. Johnson to translate "ugali" in his 1939 (rep. 1971) "A Standard Swahili-English Dictionary."