Entree: USA – Los Angeles, California – Sherry-Enhanced French Dip with Caramelized Onions and Mushrooms

Food safety reminder: Follow safe food-handling practices and use a food thermometer to verify safe internal cooking temperatures.

Serving Size: 4

Approximate Time

Prep 20 min

Cook 30 min

Additional 6 min

Total 45 min

Ingredients

- 2 tbsp (30 ml) extra-virgin olive oil
- 1 large yellow onion, thinly sliced
- 6 tbsp (85 g) unsalted butter, divided
- 8 oz (225 g) cremini mushrooms, thickly sliced
- 2 sprigs fresh thyme
- 3 cloves garlic, minced, divided
- 4 sub rolls, hinged
- 1 qt (946 ml) beef broth, warmed
- 1 1/2 pounds (680 g) very rare deli-shaved roast beef
- 2 tbsp (30 ml) dry sherry
- 1 tbsp (15 ml) Worcestershire sauce
- Creamy horseradish sauce, for serving
- Giardiniera, for serving
- Salt, to taste
- Black pepper, to taste
- 4 slices provolone or Swiss cheese (optional)

Instructions

1. Preheat the oven to 450°F (230°C). Line a rimmed baking sheet with foil.
2. In a large heavy-bottomed pot or Dutch oven, heat the olive oil and 2 tbsp (28 g) butter over medium-low heat. Add the sliced onion and salt, to taste; cook gently, stirring every few minutes, until the onions are deep golden and caramelized, 20 to 25 minutes.
3. Add the mushrooms and thyme to the onions, increase heat to medium, and cook until mushrooms release their liquid and begin to brown, about 6 to 8 minutes. Stir in 2 cloves (approx. 2) of the minced garlic, season with salt, to taste and black pepper, to taste, and cook 1 minute more.
4. Pour in the dry sherry and scrape any browned bits from the bottom of the pot. Add the warmed beef broth and Worcestershire sauce, bring just to a simmer, taste and adjust seasoning with salt, to taste and black pepper, to taste. Reduce heat to low and keep the jus warm; remove and discard the thyme sprigs if desired.
5. While the jus simmers, make the garlic butter: in a small skillet or microwave-safe bowl melt the remaining 4 tbsp (57 g) butter with the remaining 1 clove (approx. 1) minced garlic. Place the rolls cut-side up on the prepared sheet, brush generously with the garlic butter, season with salt, to taste and black pepper, to taste, and toast in the oven until golden, 4 to 6 minutes.
6. To warm the roast beef: turn off the heat under the pot so the jus is hot but not boiling. Briefly submerge small handfuls of the deli-shaved roast beef in the hot jus and lift out when just warmed through, about 15–30 seconds per portion; avoid leaving slices in the liquid where they will overcook.
7. Assemble: spread creamy horseradish sauce, to taste, on both roll halves. Pile warmed roast beef on the bottom halves, spoon a generous portion of the caramelized onions and mushrooms over the beef, and top with a slice of provolone or Swiss if using. Close sandwiches and, if melting cheese, place assembled sandwiches on the baking sheet and broil 30–45 seconds until cheese is melted.
8. Serve each sandwich with small bowls of the hot sherry-enhanced au jus for dipping, and giardiniera, for serving.