Preheat oven to 300F.

Slice the chuck roast into large chunks for easier searing. Season all sides with the salt and black pepper. Dust with flour and shake off any excess. Set aside.

Place a dutch oven over medium high heat. Add the olive oil to warm up for 1 minute, until glistening.

Sear the beef for 2-3 minutes untouched on two sides, until deeply golden and browned. If needed, work in two batches to prevent overcrowded the pot.

Reduce heat to medium, then add the sliced garlic and fresh rosemary sprig.

Add the red wine and 2 tbsp. butter to de-glaze the pot.

If you'd rather not caramelize the onions, add the onions.

Add the beef broth and worcestershire sauce. Make sure the beef is submerged in the beef broth.

Cover with the dutch oven lid to slow cook in the oven for 2.5-3 hours, until very tender.

In the meantime, caramelize the onions by place in a pan over medium high heat with the remaining 2 tbsp. butter. Season with salt.

Saute for 6-8 minutes, stirring occasionally to prevent any burning, then add 1/4 cup water and stir until evaporated. Repeat this process until deeply caramelized, about 15-20 minutes total. De-glaze the pan with the white wine. Stir until absorbed by the onions.

Slice the baguette in half lengthwise. If desired, pick out 3/4ths of the bread filling to help make room for the meat to not fall out when eating.

Drizzle with olive oil on a pan, then place in a toaster oven or the oven using the broiler to toast 1-2 minutes, until golden.

Using a slotted spoon, add the beef onto the bottom slice of toasted baguette followed by the caramelized onions and sliced provolone. Toast for 30 seconds more, just until cheese is melted.

Garnish with fresh chives, add the top baguette slice to sandwich, and enjoy immediately with the au jus (juice from the dutch oven) on the side for dipping!