Nuka-Cola Vending Machine and Gourmand's Talent on the battlefield.
You control at least one other artifact.
({2} magic symbol) if you don't control a Treasure available.
Steps
If you control a Treasure, activate it by sacrificing it, adding one mana of any color. If you don't control a Treasure, activate another artifact by paying ({2} magic symbol) , tapping and sacrificing it.
Nuka-Cola Vending Machine triggers, creating a tapped Treasure token that is also a Food due to Gourmand's Talent.
If needed, resolve the ability from step 1, causing you to gain 3 life.
Repeat.
Notes
You may activate the Treasure to instead gain life if you have ({2} magic symbol) available.