Mix all ingredients for horseradish aioli and hold in fridge. Mix all ingredients for espresso rub. Heavily rub the whole brisket and smoke at 225 for 10 to 12 hours until reaches 185 degrees. Hold at 180 until ready to serve. Sautee mushrooms and julienned onions (2 cups) until soft and brown. Spread 2 tablespoons of aioli on each hoagie roll, followed by grated cheese, brisket, mushrooms, and onion.