Measure out how much stock you plan on clarifying. You will be adding 1 egg white for every quart of stock you want to clarify. Whisk the egg whites in a bowl and set to the side.
Remove all of your stock vegetables from the bag and finely chop them up. Add these vegetables to your egg white mixture and mix well to combine
If your stock is hot you'll want to temper the egg mixture by adding a cup of hot stock to the egg mixture and gently mix it in. Once your egg mixture is tempered you can add it to your stock pot and turn the heat on a medium low. Stirring occasionally.
After 15 minutes you'll notice a layer or raft of vegetables a start to float to the top and as soon as you see that starting to form stop mixing. This will begin the process of filtering your stock.
After your raft has fully developed gently open a hole in the center with a ladle large enough to dip your ladle in. As you continue to gently simmer you'll notice that your stock will start to become crystal clear. At this point slowly ladle out the clear stock and run it through several layers of cheese cloth. Once all of the stock has been removed taste and adjust for seasonings.
To test and see if your stock has enough gelatin place a few tablespoons into a small ramekin and refrigerate for 20-30 minutes. If it sets up the way you like it you are good to go. If it's pretty soft you can add more gelatin according to the package instructions. Re-test till you get the consistency you want.