How should I warm this sliced beef?

I have about a half-pound of sliced deli roast beef. I want to make warm sandwiches but am not sure of the best way to warm it up. It is not a sandwich that gets gravy in this case, so I won’t be warming it up in gravy.

My thoughts are:
1. to put it in a baking dish with some beef broth and warm it in the oven.
2. to warm it with some beef broth in a covered frying pan on the stove.

Ideas? Hints? Thank you!