French Dip Beef Sandwiches with Onion Gravy and a Green Salad

The French Dip is built around three things: good, crusty bread; a meaty filling; and a side of gravy for dunking the whole thing into—in other words, it’s the epitome of comfort food. And if you like your food moist and dripping with juices, it’s a dream come true. After you’ve caramelized some oni...