In a bowl, combine chopped brisket and onions with the BBQ sauce.
Divide the meat mixture evenly among the wrappers, placing the meat in the centre of each wrapper.
Top meat with a pickle slice and a slice of cheddar.
Using a finger, dip it in water and run along the edges of the wrapper making all four sides wet.
Fold the wrappers by bringing up one corner over the meat into the centre of the wrapper, then bring in the sides so that the wrapper looks similar to an envelope, then roll the bottom up to the top corner.
Repeat with remaining wrappers and meat mixture.
Heat oil to 350℉
Drop brisket egg rolls into the oil one at a time, cooking only 2-3 at a time.
Cook in the oil for 2-3 minutes or until golden on all sides.
Remove egg rolls from oil and place on a paper towel lined plate or on a wire rack.
Repeat with remaining egg rolls.
Allow to cool for 2-3 minutes before serving. Inside of rolls will be hot.
Serve with additional BBQ sauce for dipping.