a simple beer braised caramelized onion dip with melted cheddar cheese & pretzel roll toasts for dipping
5 large sweet onions, thinly sliced (about 3 lbs total sliced)
½ tsp kosher salt, plus more as needed
1 (12 oz) bottle beer (use your favorite)
1 bunch thyme sprigs, tied together with kitchen twine for easy removal
½ cup mayonnaise
1 tbsp dijon mustard
½ tsp cayenne pepper
½ lb shredded cheddar cheese
½ lb pretzel rolls, sliced ¼” thick
freshly cracked black pepper
Heat a large dutch oven (or heavy-bottomed pot) over medium-high heat. Add enough olive oil to generously coat the bottom. Add the onions and salt. Cook for about 15 minutes until golden color develops, stirring often.
Stir in the beer and add the bunch of thyme. Reduce the heat to medium-low and continue to cook for about 45 minutes, until the onions are deeply caramelized and the beer has reduced. Remove the thyme. Turn off the heat and let cool for about 20 minutes. Meanwhile, preheat the oven to 400°F.
In a mixing bowl, combine the mayonnaise, dijon mustard, and cayenne pepper. Whisk until smooth. Fold in the onions and cheddar cheese. Transfer the mixture to a greased 9” cast-iron skillet. Bake for 15 minutes, or until golden and bubbling.
Meanwhile, coat the sliced pretzel rolls with a drizzle of olive oil and place onto a sheet pan in one, even layer. Season with a pinch of salt. Bake for about 10 minutes until toasted.
Remove the dip from the oven and let cool for about 5 minutes. Use a spoon to stir the dip right before serving. Garnish with any extra thyme leaves and a few cracks of black pepper. Serve with the pretzel roll toasts alongside for dipping.