French Dip Grilled Cheese

By Lily | Last modified on Feb 28, 2026

Featured in: Main Dishes

Imagine biting into a sandwich that perfectly balances melty cheese, tender roast beef, and sweet caramelized onions, all nestled between crispy French bread. The added touch of savory au jus for dipping elevates this classic comfort food into an irresistible meal that satisfies every craving.

This French Dip Grilled Cheese combines rich flavors and textures, making it an ideal lunch or dinner option that feels indulgent without being complicated. With just a bit of patience to caramelize onions and simmer a flavorful au jus, you’ll end up with a dish that’s both comforting and impressive.

Why You’ll Love This Recipe

The combination of gooey Swiss cheese and tender roast beef satisfies both cheese and meat lovers alike.
Caramelized onions add a natural sweetness that beautifully complements the savory elements.
Homemade au jus adds depth and makes every bite incredibly moist and flavorful.

Ingredients

Crusty French bread slices: Four pairs of thick, crusty bread slices that crisp up perfectly when grilled, offering a sturdy base.
Swiss cheese slices: Eight slices of mild, nutty cheese that melt smoothly and bind all the sandwich flavors together.
Thinly sliced roast beef: Approximately 340 grams of tender, juicy roast beef that adds savory richness and protein.
Yellow onions: Two medium-sized onions, thinly sliced and caramelized to bring natural sweetness and depth.
Unsalted butter: Sixty grams for cooking onions and grilling sandwiches, ensuring a golden, flavorful crust without excess salt.
Olive oil: Fifteen milliliters used with butter to evenly caramelize onions and prevent burning.
Low-sodium beef broth: Four hundred eighty milliliters for a rich au jus base, controlling salt levels.
Worcestershire sauce: Ten milliliters adds umami and tang, deepening the au jus flavors.
Soy sauce: Five milliliters enhances savory notes without overpowering.
Garlic clove: One minced clove brings aromatic freshness to the au jus.
Fresh thyme sprig: Adds subtle herbal tones that complement beef perfectly.
Salt and black pepper: To season au jus precisely to taste, balancing the richness.

Instructions

Caramelize the onions: Start by melting 1 tablespoon of unsalted butter together with olive oil over medium heat in a large skillet. Add the thinly sliced onions and cook them, stirring frequently, for about 12 to 15 minutes until they become deeply golden and fully caramelized. This slow cooking brings out their natural sugars and creates a rich, sweet flavor that enhances the sandwich.
Prepare the savory au jus: Wipe the skillet clean, then in a small saucepan combine beef broth, Worcestershire sauce, soy sauce, minced garlic, and fresh thyme. Bring it to a gentle simmer over medium heat for 5 minutes to meld flavors. Strain through a fine sieve to remove solids, then season with salt and pepper to taste. Keep the au jus warm to serve as a flavorful dip that perfectly complements the sandwich’s richness.
Assemble the sandwiches: Arrange four slices of French bread on your work surface. On each slice, layer one slice of Swiss cheese, a generous portion of roast beef, and caramelized onions. Top with another slice of Swiss cheese and finish with the remaining bread slices. This layering ensures melty cheese envelopes the beef and onions for maximum flavor and texture.
Grill until golden and melty: Spread unsalted butter evenly on the exterior sides of each sandwich. Heat a clean skillet over medium-low heat and grill sandwiches in batches. Cook each side for about 3 to 4 minutes, until the bread is golden and crisp, and the cheese has fully melted. The gentle heat prevents burning while allowing the cheese to become delectably gooey.
Serve with warm au jus for dipping: Transfer sandwiches to a cutting board and slice if desired. Serve immediately with the warm au jus on the side for dipping. This combination brings together the crispy texture, cheesy interior, savory beef, and sweet onions with the delicious depth of the broth.

You Must Know

Caramelizing onions properly takes patience but is key for sweetness and depth – don’t rush this step.
Keep the au jus warm throughout preparation to enjoy optimal flavor and dipping experience.
Use medium-low heat when grilling to avoid burning the bread before the cheese melts.

Storage Tips

Store leftover sandwiches wrapped in foil in the refrigerator for up to 2 days. Reheat gently in a skillet or oven to maintain crispness and melty cheese. The au jus can be refrigerated separately and warmed before serving.

Serving Suggestions

Pair this French Dip Grilled Cheese with a crisp green salad or roasted vegetables for a balanced meal. Add pickles or a tangy mustard on the side to cut through the richness and add brightness to each bite.

Professional Tips

Slice onions thinly and cook low and slow for perfect caramelization without bitterness.
Choose a crusty bread that holds up well when dipped in au jus to avoid sogginess.
Experiment with different cheeses like provolone or gruyere for a unique twist.

FAQs

Can I use a different type of bread?: Yes, crusty artisan bread works best for holding fillings and au jus without becoming soggy.
What’s the best cheese alternative if I don’t have Swiss?: Provolone or gruyere are excellent substitutes, offering a smooth melt and complementary flavor.
Can I make the au jus ahead of time?: Absolutely! Prepare it up to 2 days in advance, store in the fridge, and gently reheat before serving.
Is there a vegetarian alternative to roast beef?: Try substituting with grilled portobello mushrooms or seitan for a similar umami and texture experience.
How do I keep the sandwiches from falling apart while dipping?: Cut sandwiches into halves or quarters to make dipping easier and minimize mess.
Can I prepare this recipe gluten-free?: Yes, by using gluten-free crusty bread and ensuring all sauces used are gluten-free certified.