On this page of the Far Cry 6 game guide, you will find a walkthrough of the Yaran Story titled Over Easy, a side mission in the Madrugada region. The guide describes how to get to Esmeralda Eco Farm, obtain a rooster egg, and destroy other eggs effectively.
Collect a juiced-up rooster egg for Elvis
This mission will become available shortly after completing the Yaran Story, Spur of the Moment. You have to meet with Elvis again at the guerrilla hideout on the Montero Farm and receive a second order from him, this time involving "enhanced" chicken eggs.
You have to go to Esmeralda Eco Farm located northeast of the town of Verdera.
Exploring the farm, expect fighting with roosters, and just like in the previous Elvis mission, they will be extremely strong and resilient. Again, dealing with all the roosters is not possible. Take advantage of the fact that in this mission, you are operating in an open space - use sprint a lot avoiding those roosters you don't have to fight.
You can choose any rooster egg you like to steal - hold down the interaction button when you get close to one of the eggs.
Destroy the rest of the eggs
Unfortunately, there are 49 eggs to destroy, and you have to look for more throughout the entire farm - it is the yellow area on the radar.
Some eggs may be, for example, inside small buildings on the farm or under the main farm building. While searching for them, try to stay in motion so the roosters in the area won't catch up with you.
Deliver the egg to Elvis
At the very end, you have to return to the Montero farm to meet with Elvis for the last time in the guerrilla hideout. This will end the quest.