Caramelized Onion Ham and Cheese Grilled Sandwich

Prep: 15 minCook: 6 min2 servingsmediumAmerican
Caramelized Onion Ham and Cheese Grilled Sandwich

A gourmet twist on the classic grilled cheese featuring caramelized onions, artisan bread, and premium deli ham. The slow-cooked onions add sweetness that complements the tangy Dijon mustard and rich fondue cheese blend, while fresh arugula provides a peppery bite. Perfect for lunch or a satisfying dinner when you want comfort food with flavors. The combination of buttery toasted bread and melted cheese creates the ideal crispy-creamy texture contrast.

Nut-Free

Ingredients

2 servings
  • 1 large onion, thinly sliced and caramelized
  • 4 slices Heinen's whole grain artisan bread
  • 4 Tbsp Heinen's butter
  • 4 Tbsp Dijon mustard
    yellow mustard1:1preference

    less tangy

    Full guide →
  • Heinen's fondue cheese blend
    gruyere or swiss1:1availabilitydairy-free

    excellent melting

  • 6 slices Two Brothers CARE Certified deli ham, thinly sliced
  • 1 cup Heinen's arugula
    spinach or mixed greens1:1preference

    milder flavor

    Full guide →
  • 1 Tbsp olive oil

Instructions

  1. 1

    Thinly slice the onion

  2. 2

    Heat a sauté pan over medium low heat

  3. 3

    Add olive oil to the pan

  4. 4

    Add onions and cook slowly until soft and caramelized

  5. 5

    Season onions with salt and set aside

  6. 6

    Butter one side of each slice of bread

  7. 7

    Prep all toppings and have them ready near the stovetop

  8. 8

    Place two slices of bread buttered-side-down in a large skillet over medium-low heat

  9. 9

    Smear Dijon on both pieces of bread in the skillet

  10. 10

    Top with cheese, ham, arugula, and caramelized onions

  11. 11

    Place second slice of bread buttered-side-up on top

  12. 12

    Cook until bottom slice is golden brown

  13. 13

    Flip and cook for additional time

  14. 14

    Cover the pan to help cheese melt faster

  15. 15

    Remove sandwiches from skillet and place on cutting board

  16. 16

    Slice in half and serve

Tips

Tip 1

Cover the pan after flipping to create steam that helps melt the cheese more evenly and quickly.

Tip 2

Prep all ingredients before starting to cook so you can work quickly while the bread is in the pan.

Tip 3

Use medium-low heat throughout to ensure the bread doesn't burn before the cheese melts completely.

Good to Know

Storage

Best eaten immediately while hot and crispy. Can be wrapped and stored in refrigerator for 1 day but will lose crispness.

Make Ahead

Caramelize onions up to 2 days ahead. Assemble just before cooking for best texture.

Serve With

Serve immediately while hot with pickles or chips on the side.

See pairing guide →

Common Mistakes

Watch

Use medium-low heat to avoid burning bread before cheese melts

Watch

Prep all ingredients before cooking to avoid bread burning while assembling

Watch

Cover pan after flipping to help cheese melt evenly

Substitutions

Dairy-Free Swaps

fondue cheese→
gruyere or swiss1:1availabilitydairy-free

excellent melting

General Alternatives

whole grain bread→
sourdough or white bread1:1dietary

works well

arugula→
spinach or mixed greens1:1preference

milder flavor

Full guide →
Dijon mustard→
yellow mustard1:1preference

less tangy

Full guide →
Find more substitutions →

FAQ

Can I make this without caramelizing the onions?

Yes, you can use raw onion slices or skip them entirely, but caramelized onions add sweetness and depth that make this sandwich special.

What if I don't have fondue cheese blend?

Gruyere, swiss, or a combination of cheddar and mozzarella work well as substitutes for similar melting properties.

How long will leftovers keep?

Best eaten fresh, but wrapped sandwiches keep in the refrigerator for 1 day. Reheat in a skillet to restore some crispness.