Trim the fat from the beef and season it generously with salt and pepper.
Sear the beef on all sides in a pan with oil on medium-high heat.
Preheat the oven to 350°F.
Add aromatics (carrot, celery, and garlic) to the pan.
Add beef stock and stir, then add dried herbs and seasonings.
Add the beef back in with the green peppers and cover the pot.
Cook in the oven until the beef reaches ~115°F.
Remove the beef and let it rest.
Strain the jus into another pot.
Slice the beef thinly and add it back to the jus if desired.
Assemble the sandwich with all ingredients.
