1. Cut the chuck roast into six large cubes and season all sides with SPG blend seasoning.
2. Heat a Dutch oven over medium-high heat. Sear the beef on all sides until golden brown. Remove and set aside.
3. Reduce the heat to medium. Add minced garlic and cook for 1–2 minutes. Stir in thyme, bay leaf, and Dijon mustard. Deglaze with red wine, scraping the bottom of the pan.
4. Return the beef to the Dutch oven and add beef stock until the beef is covered. Bring to a boil, then remove from the burner.
5. Cover the Dutch oven and place in a 350°F oven for 3–4 hours, until the beef reaches approximately 205°F and shreds easily.
6. Cut the top off the garlic head, drizzle with olive oil, wrap in foil, and roast at 350°F for 60–75 minutes until golden and soft.
7. Melt butter in a skillet over medium heat. Add sliced onions and salt. Stir every 5 minutes until golden brown, then reduce the heat to low and continue cooking until caramelized. Finish with balsamic glaze.
8. Combine mayonnaise, roasted garlic, Dijon mustard, salt, pepper, and Worcestershire sauce in a bowl. Mix until smooth.
9. Remove the beef from the Dutch oven and shred with two forks. Strain the remaining braising liquid and keep warm for serving as au jus.
10. Slice the baguettes into eight sandwich portions and cut each portion lengthwise. Spread garlic aioli on the bottom halves.
11. Add shredded beef, caramelized onions, and provolone cheese. Arrange the open sandwiches on a baking sheet.
12. Bake at 350°F for approximately 5 minutes until the cheese melts. Top with chopped chives and the upper halves of the baguettes.
13. Slice each sandwich in half and serve with warm au jus for dipping.

Serve and Enjoy!