Ready-to-eat cereal flakes include 10 to 50 weight percent (wt %) legumes, such as black beans, and have a can weight of 19 to 22 ounces per 231 cubic inches and structural integrity similar to conventional ready-to-eat cereal flakes. The cereal flakes also include 6 to 13 wt % protein isolate, processing aid in an amount of 3 to 9 wt % and 18 to 66 wt % grains. The cereal flakes provide at least 7 grams of protein and at least 6 grams of fiber per 52 gram serving. In one process, the cereal flakes are formed by cooking and extruding a combined mass of the legumes, protein isolate, processing aid and grains without expansion of the combined mass. The extruded mass is processed in a cold pellet former and cut into a plurality of non-expanded pellets which are dried to a moisture content of 14 to 24 wt %. The pellets are then flaked at a temperature of 110 to 150° F. and dried to a final moisture of 1 to 5 wt %.
