Activate Umbral Collar Zealot by sacrificing Kitchen Finks.
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 3 life.
Cleric Class triggers, putting a +1/+1 counter on Kitchen Finks.
Resolve the Umbral Collar Zealot ability.
Repeat.
This loop relies on an endless cycle of sacrifice and rebirth to churn through your deck and rack up infinite resources. You begin by using Umbral Collar Zealot to sacrifice Kitchen Finks, sending the stubborn defender to the graveyard and triggering its persist ability to bring it right back with a -1/-1 counter. Thanks to Cleric Class—specifically its static ability boosting your life gain and its Level 2 trigger—every time Kitchen Finks re-enters, the life you gain is boosted and immediately counters the -1/-1 penalty by placing a +1/+1 counter on it, resetting its state so the process can begin anew.