Heat the olive oil in a medium skillet over medium heat.

Add the onion, season with salt and pepper to taste.

Cook, stirring occasionally, for 7 to 8 minutes, or until the onion has softened and begun to brown.

Add the garlic, bell pepper, mustard, Worcestershire, and hot sauce to the pan.

Continue to cook, stirring occasionally, until the peppers are soft and the onions are brown, about 7 minutes more.

Add the flour and cook, stirring constantly, for about 1 minute, then slowly add the stock to the pan.

While stirring constantly, bring to a simmer and then continue to stir for 3 to 4 minutes, until the mixture has thickened.

Remove from the heat.

Cut the rolls in half and toast to desired doneness in a toaster oven.

Spread barbecue sauce on each side.

Add the brisket slices to the onion-pepper mixture in the pan and stir just to combine.

Once brisket is warm, transfer the brisket slices along with some onions and peppers into each sandwich.

Serve immediately