Caramelize the onions

1. In a large pan (caste iron preferred), heat the oil on medium heat until sizzling, then add in the onions. Sprinkle with salt and turn heat to low. Stir the onions every 5-10 minutes for 1 hour 30 minutes. Once the onions get light golden brown and sticky, it’s time to pour in the wine. This time could vary based on different stovetops, so go by the color of the onions over the actual time. Pour in 1/2 cup of wine every 5 minutes until you’ve poured in 1 1/2 cups, stirring in between each addition. The onions should develop a beautiful magenta-red color that gets more intense the longer it cooks. Cook for an additional 10-15 minutes, then remove from heat. You can store the onions up to 4 days in the fridge.

Make the burgers

1. Combine the bread and milk in a small bowl, allowing the bread to soak up the milk. Mix it around a little with your fingers so it forms a wet paste.
2. In a large bowl, combine the rest of the ingredients with the soaked bread and milk, mixing thoroughly. Form into 2 ounce patties roughly 3/4″ thick (tip: to get even burgers each time, divide the mixture in half, then each half in half, then those halves in half for 8 equal pieces). Allow to sit for 15 minutes so that everything can marinade together.
3. Heat a large flat-bottomed pan on medium heat. Cook the sliders for roughly 2 minutes on each side, until fully cooked through.
4. To assemble, place a patty on a toasted slider bun. Top with 1 ounce goat cheese, 1-2 tablespoons of the red wine caramelized onions, and arugula. I also slathered on some dijon mustard, which added an awesome kick!