A grill and a burner assembly therefor. The burner assembly utilizes a V-shaped firebox having a V-shaped combustion chamber containment wall, which defines a combustion chamber of significantly reduced volume. The burner assembly can also have a V-shaped outer insulating wall which is positioned outside of the combustion chamber containment wall such that an insulating gap is formed between the inner V-shaped wall and the outer V-shaped wall. A burner element preferably extends longitudinally within the combustion chamber of the firebox above the bottom of the V-shaped combustion chamber containment wall.