Karaaz in Stormspire, Netherstorm and Paulsta'ats near Oshu'gun in Nagrand both sell the Recipe, which requires Exalted with The Consortium. Consortium Reputation can be earned through questing in Nagrand, Netherstorm, as well as running Mana-Tombs on Normal or Heroic.

The Consortium is a friendly cartel of Ethereals that operate in several zones such as Netherstorm and Nagrand. In this guide, we will cover how to gain reputation with them and rewards for the Consortium.
Led by Nexus-Prince Haramad, the Consortium are ethereal smugglers, traders and thieves that have come to Outland to benefit from their riches. Their main base of operations and biggest settlement is the Stormspire in Netherstorm, but they can be found at Midrealm Post, Aeris Landing in Nagrand, within the Mana-Tombs of Auchindoun and various other places.
Upon reaching Friendly status, players are officially considered members of the Consortium and given a salary. The salary is a bag of gems at the beginning of every month, given by Gezhe at Aeris Landing. Higher reputation with the Consortium yields higher qualities and quantities of jewels each month.
How to Gain Reputation
Players begin their reputation with The Consortium at Neutral, and the process of gaining reputation with them generally requires completing one-time quests which will then unlock repeatable quests with item turn-ins. Some of these repeatable quests unlock at specific reputation levels, which can be a bit confusing to follow.
You can obtain reputation with the Consortium in the following ways:
Consortium Quests: Neutral to Exalted
 Oshu'gun Crystal Fragment and  Pair of Ivory Tusks turn-ins: Neutral to Friendly
 Obsidian Warbeads and  Zaxxis Insignia turn-ins: Friendly to Exalted
 Ethereum Secrets turn-ins: Honored to Exalted
 A Thousand Worlds turn-ins: Revered to Exalted
Mana-Tombs runs:
Normal Mana-Tombs - Neutral to Honored
Heroic Mana-Tombs - Neutral to Exalted
Since reputation gains with the Consortium are a bit convoluted due to many of the repeatable turn-in quests requiring specific reputation standings, we'll be detailing how to gain reputation with them at each specific reputation levels.
Neutral to Friendly
You can start gaining reputation with the Consortium at level 64.
To gain reputation with the Consortium in Nagrand:
Find a Consortium Recruiter near Telaar or Garadar and accept the quest  The Consortium Needs You!. This breadcrumb offers 10 reputation and starts the Consortium questline in Nagrand.
Once you reach Aeris Landing in Nagrand, you can pick two quests -  A Head Full of Ivory and  Stealing from Thieves. Only turn-in ONE of these quests, then pick up the repeatable version (either  More Heads Full of Ivory or  More Crystal Fragments) and do repeated turn-ins until you reach Friendly. Once you reach Friendly, complete the other unique quest - This will allow you to get some extra reputation as you reach friendly.
You will need 12 turn-ins of either quest to reach Friendly. Both required items,  Oshu'gun Crystal Fragment and  Pair of Ivory Tusks, are not bound to anything and thus can be purchased from the Auction House.
In addition to this, you can run Mana-Tombs on either Normal or Heroic (if you are 70) to gain reputation with the Consortium.
Friendly to Honored
At Friendly, you will gain access to the quest  Obsidian Warbeads at Aeris Landing in Nagrand, which requires you to obtain 10  Obsidian Warbeads from the ogres and Kil'sorrow agents in the zone. Completing this quest grants you 250 Reputation with the Consortium, and grants access to the repeatable quest  More Obsidian Warbeads, which allows you to continuously farm Obsidian Warbeads for reputation with the Consortium. You can farm in Nagrand if you're interested in farming reputation with the Kurenai or The Mag'har at the same time (as ogre/kil'sorrow kills grant reputation to both factions) as the Consortium, or if you're grinding for  Oshu'gun Crystal Powder Sample for the Halaa PvP Talbuk mounts.
At level 67, you are also able to start questing in Netherstorm. During your quests in Netherstorm, you will unlock the repeatable quest  Another Heap of Ethereals, which grants you 250 Reputation per 10  Zaxxis Insignia. Zaxxis Insignias can be farmed from the hostile ethereals found south of Area 52.

You are able to complete Consortium quests in several areas of Netherstorm. The list of quests per area in Netherstorm is located below:

At level 68, you will unlock quests in two other locations in Netherstorm: Tuluman's Landing and Protectorate Watch Post. These quests grant more reputation with the Consortium, and it is especially important to complete the Protectorate Watch Post questlines, as this will open up more reputation farming methods at Honored and beyond.

In addition to this, you can continue running Mana-Tombs on either Normal or Heroic to gain extra reputation. Normal Mana-Tombs will grant reputation only until Honored, while Heroic Mana-Tombs will grant reputation all the way to Exalted.
Honored to Exalted
 Obsidian Warbeads turn-ins,  Zaxxis Insignia turn-ins, Heroic Mana-Tombs runs and the quests mentioned before this portion of the guide will continue granting reputation all the way to Exalted, so keep doing these to earn more Reputation.
At Honored, a new questline will unlock at the Protectorate Watch Post. This questline will cause ethereal mobs in Outland to start dropping  Ethereum Prison Key. Ethereum Prison Keys are used to open Ethereum Prisons, spheres containing prisoner mobs at the Ethereum Staging Grounds in Netherstorm. Opened prisons will either reveal friendly NPCs that will grant 500 Reputation to a random Outland faction, or hostile NPCs that, when defeated, drop  Ethereum Prisoner I.D. Tag, which can be turned in at the Protectorate Watch Post for 250 Reputation with the Consortium.

The hostile mobs from Ethereal Prisons can be hard to solo, so gathering a group to farm them is highly advised. In addition to this,  Ethereum Prison Key are not bound to anything, so you are able to purchase them from the Auction House. To unlock Ethereal Prison Key drops, you must complete the following questline:

At Revered, another questline will open at the Protectorate Watch Post. This chain is a continuation of the Ethereal Prison Key questline, which will eventually lead to another reputation farming method - Stasis Chambers at Bash'ir's Landing in Blade's Edge Mountains. These Stasis Chambers require a special key, the  Ethereum Stasis Chamber Key, which can be obtained by turning in 5  Ethereum Prison Key.

The Stasis Chambers contain powerful elite mobs that have a chance to drop  Mark of the Nexus-King, a currency that is used to open a special Stasis Chamber in Heroic Mana-Tombs, and allows the player to summon an extra boss - The voidhound Yor. This is considered to be the final questline for the Consortium, containing the following quests:

Karazhan Vendor
A Consortium-aligned vendor can be found in Karazhan. Ythyar can be found in the room preceding the Chess Event encounter, and serves not only as a repair vendor, but also sells some patterns to those that have raised their reputation with the Consortium. Ythyar sells the following wares:

Vendor Rewards
The Consortium has two quartermaster NPCs: Paulsta'ats at Aeris Landing in Nagrand and Karaaz atop the Stormspire in Netherstorm. Both NPCs sell the same wares so you can go to either of them to purchase your rewards.