Transfer the egg back and forth between to two half shells allowing the egg white to drip down into a bowl below you. Continue to pass the yolk back and forth between the shells until all the whites are in the bowl and the only thing left in the shell is a yolk. Save this yolk for another recipe or discard it.
Use your electric mixer to whip the egg whites on high for a few minutes until you have soft peaks. You’ll know you have “soft peaks” when you lift your mixer and the egg white forms a small little mountain with a “peak” but then melt back down into itself fairly quickly.
Place the agave nectar in a pot over medium-high heat and heat until it reaches a temperature of 240F. I used this digital candy thermometer to gauge the temp.
Continue to whip the egg whites with your mixer and slowly pour the hot agave syrup into the egg whites. It will be super hot so be careful not to splatter.
Continue to whip for about 5 minutes until you get firm peaks. Firm peaks are when you lift the electric mixer out of the bowl and egg white mountain peaks are stiff and upright and don’t fall back into themselves.