Replace the gasket. Use RTV silicone sealant (Hondabond) to better the seal between the pan to gasket to block.
RTV stands for Room Temperature Vulcanizing. It refers to sealant that vulcanizes (cures) at room temp. You use it to better the seal between parts such as the valve cover gasket and the cylinder head, as well as the oilpan gasket to the oil pan.
Some people use it instead of replacing the gasket. This is possible, but is not as reliable as simply replacing the entire gasket.