Grilled French Onion Egg Salad Sandwich

In a skillet over medium-low heat, add olive oil. Add the thinly sliced onions and a pinch of salt. Cook slowly, stirring occasionally, until deeply caramelized. Set aside.

Bring a pot of water to a boil. Gently lower in the eggs and cook for exactly 8.5 minutes.

Immediately transfer the cooked eggs to an ice bath to stop the cooking process. Let them cool completely.

Peel the cooled eggs and roughly chop them. Transfer to a mixing bowl.

To the bowl with the chopped eggs, add mayonnaise, Dijon mustard, Worcestershire sauce, the reserved caramelized onions, onion powder, fresh thyme, salt, and pepper.

Gently mix all the ingredients together until just combined.

Spread the egg salad mixture evenly on one slice of sourdough bread.

Top the egg salad with shredded Gruyère cheese and place the second slice of bread on top.

Melt butter in a skillet over medium heat. Carefully place the sandwich in the pan.

Grill the sandwich for 2-3 minutes per side, until the bread is golden brown and toasted, and the cheese is fully melted.

Remove the sandwich from the pan. Garnish with chopped fresh chives and a sprinkle of flaky sea salt.

Slice in half and serve immediately.