the invention concerns a method for a lean gas combustion using at least one burner including a combustion nozzle on a central axis . the method includes creating a mixture of fuel gas and combustion air rotating about the central axis , and ejecting a flow of non - flammable premix containing a mixture of premix air and fuel gas in front of the combustion nozzle . a complementary flow achieves a non - flammability threshold of the mixture in front of the combustion nozzle , the flow being ejected at the center of the premix flow via a central complementary flow and / or about the premix flow via a peripheral complementary flow . the invention also concerns a burner configured to implement the method and a combustion installation using same .