Majority of the populations of Ethiopia highly rely on Biomass in traditional and inefficient way of cooking which have harsh effect on both human health and global climate. Solar cookers can be an alternative which can cook food without burning any wood. But a solar cooker cannot replace the traditional energy source completely, because of there will be days and hours the sun doesn’t provide enough power to cook. In this work, design, fabrication and testing of portable solar-biomass combined cook stove has been done with an intension of using the benefit of the free solar energy in order to use lower daily fuel consumption and to use the biomass when the solar is not enough. The test was done by using only biomass, solar and combined energy sources for cooking. The water boiling test was done to measure performance metrics when only biomass is used and when biomass is used with the reflectors under sunshine. The results show that the biomass stove with reflector under sun gives a 5 % thermal efficiency increase and 6 g/liter decrease in fuel consumption when compared to the biomass only stove. From the performance merit tests when only solar box oven used the first figure of merit was found to be 0.1154 and second figure of merit found to be 0.55. It shows that there is a good heat transfer to the contents in the vessel. Also the box top used to dry biomass when the stove is not used for cooking and 11.1% moisture difference determined using moisture analyzer after drying it for two days. The extended surface heat plate was tested to see the effect but does not provide enough of a boost in efficiency because of the losses associated with thermal capacitance and contact resistance. It was seen that even if finned plate is a low-cost alternative it is better to use finned pots. Economic benefit of the overall system was evaluated and the payback period for household purchasing firewood is found to be 3 months.