This Bartender is located in the Bar at Falador. You can talk to this Bartender to start the Recipe for Disaster mini game/quest.
This Bartender gives you to option to play the minigame or look at his shop. If you haven't done the mini game yet the shop will contain: Bronze Gloves, Iron Gloves, Steel Gloves, Black Gloves, Mithril Gloves and Ava's Accumulator.
See: "Recipe for Disaster".
If you manage to defeat Agrith-Na-Na, Adamant Gloves get added to the shop. Rune Gloves get added if you slay Flambeed. Dragon Gloves if you defeat Karamel and Barrows Gloves if you kill Dessourt.