French Dip Recipe

Heat a large skillet over medium-low heat. Add 1 tbs butter and 1 tbs olive oil to the pan.

Add the thinly sliced onions and 1/2 tsp salt. Toss to coat and spread into an even layer.

Cook gently, stirring every 4–6 minutes, adjusting heat so onions sizzle lightly but do not burn. After about 20–25 minutes they will soften and begin to brown at the edges.

If using, sprinkle the brown sugar over the onions at 20 minutes to accelerate browning and enhance sweetness.

Continue cooking another 10–15 minutes until onions are deeply golden-brown and jammy. Stir in remaining 1 tbs butter at the end for shine and flavor. Remove from heat and keep warm.

In a medium saucepan combine 3 cups beef stock, 1/4 cup beef drippings or demi-glace (if using), 1 tbs soy sauce or Worcestershire, smashed garlic cloves, and thyme sprigs.

Bring to a gentle simmer over medium heat, then reduce to low and simmer 10–12 minutes to concentrate flavors.

Taste and season with 1/4 tsp salt and 1/4 tsp black pepper. Strain the jus into a heatproof bowl, discarding solids. Whisk in 1 tbs cold butter until glossy. Keep warm; transfer to small dipping bowls for serving.

Cut potatoes into 1/4–1/2" sticks. Place cut fries in a bowl of cold water and soak 30 minutes to remove excess starch; for best results, soak up to 2 hours in the refrigerator.

Drain and rinse the potatoes, then dry thoroughly with towels. Toss with 1 tbs cornstarch (optional) for a crispier exterior, then season lightly with 1 tsp salt and 1/2 tsp pepper.

Heat oil in a heavy pot or deep fryer to 325°F (160°C). Fry potatoes in batches for 3–4 minutes until soft but not browned. Remove and drain on a rack or paper towels.

Increase oil temperature to 375°F (190°C). Fry the par-cooked fries again in batches for 2–3 minutes until golden and crisp. Drain, season immediately with a pinch more salt if desired, and keep warm.

Preheat oven to 400°F (200°C) (or use a broiler). Split French bread loaves lengthwise, creating sandwich halves; remove some interior crumb if desired to better hold meat and jus.

Lightly brush cut bread interiors with the remaining 3 tbs butter and 1 tbs olive oil mixture, then season with a light pinch of salt and pepper.

Layer thinly sliced prime rib evenly across the bottom halves of the loaves. Divide the caramelized onions evenly over the beef.

Top the meat and onions with provolone slices (about 2 slices per sandwich half). Close the sandwich halves and place on a baking sheet.

Warm the assembled sandwiches in the oven for 6–8 minutes until the cheese is melted and bread is slightly toasted. For a crisper top, place under the broiler for 1–2 minutes—watch closely to avoid burning.

Remove from oven, cut each loaf into 4 sandwiches (or desired portions). Serve immediately with small bowls of warm au jus for dipping and a generous portion of hand-cut fries on the side.