Croque Monsieur with Crispy Fries and Simple Salad

Think golden, melty croque monsieur vibes—then add crunchy fries and a bright little salad to cut through all that comfort. This version is designed for weeknight flow: a quick mustard vinaigrette, oven-crisp (or double-fried) fries, and a sandwich that’s toasted until bubbling and deeply golden.

Recipe at a glance

• Yield: 4 sandwiches + fries for 4
• Prep time: 25 minutes
• Cook time: 35 minutes
• Chill time: 0 minutes (vinaigrette can be mixed up to 24 hours ahead)
• Total time: about 1 hour

Ingredients

For the croque monsieur

• 8 slices sturdy bread (sourdough, country white, or sandwich bread)
• 8 slices ham (about 8 ounces total)
• 1 1/2 cups shredded Gruyère (or Swiss-style cheese), divided
• 1/2 cup grated Parmesan (optional, for extra flavor)
• 2 tablespoons unsalted butter
• 2 tablespoons all-purpose flour
• 1 1/2 cups milk (whole or 2%)
• 1/2 teaspoon Dijon mustard
• 1/4 teaspoon ground nutmeg (optional)
• Kosher salt and black pepper, to taste
• 2 tablespoons mayonnaise (optional; for a lightly crisp, tangy top)
• 2 tablespoons unsalted butter (for toasting in the pan)

For crispy fries (choose one method)

• Double-fry method:
  • 1 1/2 pounds russet potatoes, scrubbed
  • 2 to 3 quarts neutral oil (peanut, canola, or vegetable), for frying
  • Kosher salt, to taste
• Oven-crisp alternative:
  • 1 1/2 pounds russet potatoes, scrubbed
  • 1 to 2 tablespoons cornstarch
  • 3 tablespoons neutral oil
  • 1 teaspoon kosher salt, plus more to finish
  • Optional: 1/2 teaspoon smoked paprika or garlic powder

For the simple salad + mustard vinaigrette

• 6 cups mixed greens (arugula, romaine hearts, spring mix)
• 1 small cucumber, sliced (optional)
• 1/2 cup cherry tomatoes, halved (optional)
• Mustard vinaigrette:
• 3 tablespoons Dijon mustard
• 2 tablespoons apple cider vinegar (or white wine vinegar)
• 1 tablespoon honey or maple syrup (optional, for balance)
• 1/3 cup extra-virgin olive oil
• 1/4 teaspoon kosher salt (plus more to taste)
• Black pepper, to taste

Optional serving extras

• Extra Dijon, chopped parsley, or lemon wedges
• Ramekin of whole-grain mustard

Instructions

1) Make the vinaigrette (quick and forgiving)

1. In a small bowl or jar, whisk (or shake) Dijon, vinegar, honey (if using), salt, and pepper.
2. Drizzle in olive oil while whisking until smooth. Taste and adjust—more vinegar for tang, more honey for mellow.

2) Prep fries (start while you cook the sandwich components)

1. Peel potatoes if you like. Cut into evenly sized fries (about 1/4 to 1/3 inch thick) so they cook at the same rate.

3) Cook the fries (choose your method)

Double-fry method (crispest)

1. Heat oil in a deep pot to 325°F (medium-low). Pat fries dry.
2. Fry in batches until pale-golden and tender, 4 to 6 minutes. Do not brown much yet.
3. Transfer to a rack or paper towels and cool 10 minutes (they should look steamed, not browned).
4. Increase oil to 375°F (high enough for active bubbling). Fry again until deep golden and crisp, 2 to 4 minutes.
5. Drain well, season immediately with salt. For best texture, serve right away.

Oven-crisp alternative (lower effort)

1. Heat oven to 450°F. Line a sheet pan with foil or parchment and place a second rack on top if you have it.
2. Boil cut fries in salted water until just barely tender, 7 to 9 minutes. Drain well.
3. Toss fries with cornstarch, oil, and optional seasonings.
4. Spread in a single layer (use two pans if crowded). Bake 20 minutes, flip, then bake 10 to 20 minutes more until deeply golden at the edges.
5. Season with salt. Fries soften after cooling—recrisp briefly at 450°F for 5 to 8 minutes if needed.

4) Make the melty sauce (quick mornay-style)

1. Melt butter in a saucepan over medium heat. Whisk in flour and cook 1 minute to form a smooth roux.
2. Slowly whisk in milk. Keep whisking until the sauce thickens, about 3 to 6 minutes.
3. Remove from heat and stir in Dijon, nutmeg (if using), 1 cup shredded Gruyère, and Parmesan (if using). Season with salt and pepper.
4. Texture cue: the sauce should coat a spoon thickly, like a creamy custard.

5) Assemble croque monsieur

1. Set a large skillet over medium-low. (You want steady heat so the bread toasts before the cheese scorches.)
2. Spread one side of each bread slice with the optional mayonnaise (this helps browning). Place 4 slices in the skillet, mayo-side down.
3. Top each with a layer of ham.
4. Spoon sauce over the ham and add remaining Gruyère (and a little extra if you like a heavy melt).
5. Top with the remaining bread slices, mayo-side up.

6) Toast until golden and bubbly

1. Melt 1 tablespoon butter around the sandwiches (in the pan) and cook 3 to 5 minutes until the bottoms are deep golden.
2. Flip carefully and cook another 3 to 5 minutes until the second side is golden and the cheese is bubbling.
3. Texture cues: the top should look crisp, with visible melted cheese at the edges.

7) Toss the salad and serve

1. In a large bowl, toss greens with a few spoonfuls of vinaigrette (start with less; you can always add more).
2. Serve each sandwich with a pile of fries and a side salad.

Quick tips

• Keep fries crisp: After frying, hold on a rack (not a plate) and salt at the end.
• Don’t rush the sandwich heat: Medium-low prevents burnt bread and gives the center time to fully melt.
• Extra flavor swap: Stir 1/2 teaspoon Worcestershire into the sauce for deeper savoriness.
• Ingredient variation: Swap ham for turkey deli slices or even sautéed mushrooms for a meatless option (thinly sliced mushrooms cook faster).

Serving ideas

• Serve with lemon wedges for brightness and an extra ramekin of Dijon or whole-grain mustard.
• Add a few sliced radishes or chopped herbs to the salad for crunch.

Storage notes

• Sandwiches: Cool to room temperature briefly, then refrigerate within 2 hours. Store up to 3 days.
• Fries: Best fresh. Leftovers keep 2 to 3 days in the fridge; reheat in an 450°F oven or air fryer until crisp again.
• Salad greens: Store vinaigrette separately if possible to keep greens crisp. Refrigerate prepped salad up to 2 days.
• Reheat for best texture: Warm sandwiches in a 350°F oven until hot and melty, rather than microwaving.
• Freezing: Sandwiches freeze best without fries. Wrap well and freeze up to 2 months. Thaw in the fridge, then reheat in the oven. (Fries don’t re-crisp as nicely after freezing.)

Sources

• FDA — Safe Food Handling (2-hour rule and refrigeration guidance)
• Food Network — Double-Fried French Fries (method/temperature cues)
• Martha Stewart — Classic Croque Monsieur (ingredient/melt context)