Crafting the hard tack used by dwarf explorers is a community effort. To participate in the event you need to learn three recipes. Fortunately, these are easily learned.
'If you are willing to assist us in our efforts to craft hard tack, then I shall teach you the recipes necessary for our endeavour here.
'Speak with me again and I will explain.'
Speak with Ingúl Ovestoke near the ovens in Ukhbab-gairu to learn the recipes needed to participate in the Hard Tack of Thorin's Hall event.