When Kitchen Finks dies, its persist ability triggers, returning Kitchen Finks from your graveyard to the battlefield with a -1/-1 counter on it.
When Kitchen Finks enters the battlefield, it triggers, causing you to gain 2 life.
Heliod triggers, putting a +1/+1 counter on Kitchen Finks.
Resolve the Yahenni ability.
Repeat.
This elegant loop centers on the relentless resilience of Kitchen Finks, which returns to the battlefield via persist with a -1/-1 counter after being sacrificed to Yahenni, Undying Partisan. That entry triggers a life gain event, which in turn wakes up Heliod, Sun-Crowned's passive life-trigger to place a +1/+1 counter on Kitchen Finks. Because +1/+1 counters and -1/-1 counters simultaneously cancel each other out as a state-based action, Kitchen Finks is left completely clear of counters and ready to be sacrificed all over again. Yahenni, Undying Partisan even provides a handy outlet to protect your board with temporary indestructible if the situation calls for it.