In newly designed burner, the main mixing tube is fitted with lower part of the burner barrel tangentially at 30 degree inclination with the barrel horizontal axis so that perfect homogeneous mixing of pre-flame mixture can be achieved due to swirling motion of mixture inside of barrel for tangential entry of high velocity mixture from main mixing tube. For swirling motion of flame, contact with cooking pot is also increased for better heat transfer to cooking pot. In the new burner, a co-axially placed inner mixing tube is provided inside of main mixing tube, which is made active during slow cooking to create comparatively higher rate of pressure drop inside of tube for which sufficient air is available even gas jet velocity is low. As a result, ideal blue flame combustion is achieved throughout the entire range of cooking.