I had this at the Tamambo Restaurant in Nairobi. It was very good and had the clever name of "Kachos" (Kenyan Nachos). The chips (crisps) were arrow root and potato. These were topped with a pico de gallo type salsa, melted cheese, chilis and a very good and interested whipped type sour cream spiked with lime. This would be very easy to make at home. I would try cassava root chips or sweet potato chips too.