A burner apparatus and process are described. The burner apparatus includes an inlet chamber in communication with a combustion chamber. A primary conduit delivers fuel gas to the combustion chamber. Each of a plurality of primary tips is located in the throat of the burner tile. Each of a plurality of cavities is disposed on a downstream wall of the burner tile and stabilize the flame. The primary tips have an end port and a lateral port. A secondary conduit provides fuel gas to a plurality of secondary tips. In a passive control mode, the fuel gas to the primary tips and secondary tips is a mixed gas comprising flue gas and fuel gas. In an active mode, valves are provided to proportion the amount of fuel gas fed to the primary tips and the amount of flue gas provided to the secondary tips.