Man oh Man Heath….you’re on a ROLL the last two days from Grammy’s fried chicken sandwich to the pellet smoked brisket and now this brisket sandwich! You are on a ROLL!
No brisket ever goes to waste around here. All the trimmings go to beef tallow, and scraps for the crows. Slices for endless sandwiches, point for burnt ends, and more point meat and scraps make for great meat in chili. Grilled Cheese? Great idea and just another use for brisket.
Instead of this you should have just done a Patty Melt and added the caramelized onions. FYI, using mayo is no substitute for the taste of toasted butter soaked bread
Can make it your own and add or substitute whatever you like. I know mayo doesn't overall make a difference. I like to add a layer to the bread before grilling it. Can do butter if you prefer.