French Dip with Onion Jus
The onion jus and aioli can be refrigerated separately for 2 days; reheat the jus before serving. The beef can be roasted 1 day ahead and refrigerated unsliced.
You can substitute 1 cup of mayonnaise for the egg yolks in the aioli; cut the canola oil to 1/2 cup. Banyuls vinegar is an aged sweet wine vinegar from the south of France. Cave de L'Abbé Rous makes a very good version; it's available from amazon.com.
Over-the-top sandwiches like this one go best with a big, juicy red wine, like Garnacha from Spain.