The best recipe would be a level 15 blue recipe that boosts both health and stamina. However, you must have the appropriate passive unlocked in Provisioning to be able to make it, though you could buy the food at a guild kiosk or from another player. The next best is a level 15 green recipe that boosts either health or stamina. This would not require any skill points in Provisioning, but would only boost one of the stats.
@Phatalix Meet me later tonight at the cooking pot by the banker at the South Morrowind Gate and I will make you a stack of blue Health and Stamina food for both level 15 and level 20 or 25, your choice. I don't want a guildie to enter battle on an empty stomach.