• Milk ½ cup
  • Butter, 1oz
  • All-purpose flour, 2 tablespoons
  • 2 oz onion, chopped
  • 2 large slices of bread
  • 5 oz. Mild to sharp cheddar cheese
  • 2 oz. Gruyere cheese or other white cheese
  • 1 teaspoon Ground mustard
  • Pinch of nutmeg
  • Salt and pepper to taste


  1. Add butter and onion to a medium-sized saucepan. Sweat the onion for about 5 minutes or until the onion is soft and translucent.
  2. Add the flour, stirring vigorously until a blond paste is formed.
  3. Add the milk in 2 batches, continuing to stir until the sauce can coat the back of a spoon when dipped. Add your gruyere cheese, stirring slowly until the sauce is evenly thickened. Season with salt and pepper.
  4. Add cheddar cheese to both slices of bread. Fry the slices of bread on in butter on medium-high heat in a pan big enough to fit the slices side to side. You can cover the pan with a lid to aid the cheese melting.
  5. After about 3-5 minutes, carefully flip on slice onto the other, taking care to not spill the sliced cheese. Press the sandwich with a spatula to crisp the bottom. After about another 3 minutes, flip the sandwich and repeat.
  6. Transfer the sandwich onto a tray and top with the cheese sauce that was made earlier. You’re welcome to add additional Gruyere as you would like
  7. Place under a broiler. If you have a Wolf Dual Convection Oven, place on rack position 2 and set the oven to Broil. After about 2 minutes you will want to watch the sandwich as browning can occur very quickly.
  8. Once the cheese and browned and is gooey, pull the sandwich from the oven. Slice in half and garnish with some salad greens, microgreens, or sprouts if you have them.