Ingredients:

  • 3 large yellow onions (900g), thinly sliced
  • 3 tbsp unsalted butter
  • 1/4 tsp baking soda
  • 1/2 tsp kosher salt
  • 1 tbsp balsamic vinegar
  • 8 oz (225g) full fat cream cheese, softened
  • 1/2 cup (120g) plain Greek yogurt
  • 1/4 cup (60g) high-quality mayonnaise
  • 2 cloves garlic, minced
  • 1 tsp fresh thyme leaves, chopped
  • 1/2 tsp freshly cracked black pepper
  • 6 oz (170g) Gruyere cheese, freshly shredded
  • 1/4 cup (25g) grated Parmesan cheese

Instructions:

  1. Melt butter in a large skillet over medium-high heat. Add the sliced onions and salt.
  2. Cook onions for approximately 5 minutes until they begin to soften and hiss. Sprinkle the baking soda evenly over the onions to accelerate the Maillard reaction.
  3. Continue to stir constantly as the onions transition to a deep mahogany brown and jammy consistency, about 15 minutes total.
  4. Deglaze the skillet with balsamic vinegar, scraping the bottom of the pan to incorporate the savory fond. The liquid should evaporate within 30 seconds. Remove from heat and allow to cool slightly.
  5. In a medium mixing bowl, beat the softened cream cheese until smooth. Fold in the Greek yogurt, mayonnaise, minced garlic, fresh thyme, and black pepper.
  6. Incorporate the warm caramelized onions and half of the shredded Gruyere into the cream cheese mixture.
  7. Transfer the mixture to a small baking dish or back into the oven proof skillet. Top with the remaining Gruyere and the Parmesan cheese.
  8. Bake in a preheated oven at 200°C for 20 minutes until the cheese is bubbling and the top is golden brown.