({2} magic symbol) ({G} magic symbol) ({W} magic symbol) plus enough mana to pay for commander tax, if applicable available.
Steps
Cast
Farmer Cotton either from your hand or from the command zone by paying ({2} magic symbol) ({G} magic symbol) ({W} magic symbol) and commander tax, if applicable.
When
Farmer Cotton enters the battlefield, it and
Cloudstone Curio trigger.
Resolve the
Cloudstone Curio trigger, choosing to return nothing to your hand from the battlefield.
Resolve the
Farmer Cotton trigger, creating two 1/1 Halfling creature tokens and two Food, two Clue and two Treasure artifact tokens.
When the Halflings enter the battlefield,
Cloudstone Curio triggers twice.
Resolve the first trigger, returning
Farmer Cotton to your hand from the battlefield.
Resolve the second trigger, choosing to return nothing to your hand from the battlefield.
Activate the two Treasures by tapping and sacrificing them, adding ({G} magic symbol) ({W} magic symbol) .
Activate
Ashnod's Altar by sacrificing a Halfling, adding ({C} magic symbol) ({C} magic symbol) .
Repeat.
Once you have infinite Halfling tokens, you may sacrifice them to get infinite colorless mana, which can be used to cast
Farmer Cotton for an arbitrarily large amount of mana to create infinite Treasure tokens.