Season the beef with salt and pepper.

Heat the oil in a pot on medium heat. Saute the onions until softened and starting to brown. Then stir in the broth, beef, and rosemary. Bring to a low simmer until the flavor concentrates, about 15 to 20 minutes. Then add in the butter. Taste and season with salt and pepper to taste. Reserve the au jus for serving.

Preheat the oven broiler on low. Slice open the rolls and place them on a baking sheet. Toast the bread under the broiler until golden brown (keep a close eye on the bread so that it doesn't burn).

Using tongs or a slotted spoon, place the beef on the roll.

Mix the sparkling water and lemon. Serve over ice if desired.

Serve the French dip with au jus, apples and peanut butter, and lemon sparkling water.