Soak beans overnight. Drain and cook in unsalted water together with pork fat or bacon until soft.
Remove from heat and let cool. Beat with a wooden spoon to form a coarse purée. Set aside and let cool.
Heat oil in a large skillet and add onion, garlic and aji. Saute onion and aji until soft and tender and correct seasoning. Add the beans and the cooked rice, mix well and correct seasoning. Cook stirring, until golden and remove from heat.
To make the tacu tacu:
Take one part of the mixture into your hands and form a small oblong tamale.
Cover with bread crumbs or crackers to maintain shape.
Heat oil in skillet, place one part of the bean mixture, and fry turning constantly to avoid sticking. Repeat with the rest of the mixture.
Serve with breaded fried tenderloin, fried banana, fried egg and Creole sauce.