Start in Falador, in the Rising Sun Inn, east of the west bank. Talk to Emily. Ask her what she can tell you about "dwarves and ale". She will offer to tell you the secret recipe for Asgoldian ale for the price of 200 coins ( free with an activated Ring of Charos, for 100 coins and a plain pizza, or for 50 gold and a chocolate bar). Look for an "Old Dwarf" (later named Rohak) in the bar area. Talk to him. He will refuse to give his recipe for Dwarven rock cake to you, but he will mention the Rising Sun Inn.