01 - Preheat your oven to 425°F (220°C). Line a large sheet pan with parchment paper for easy cleanup.
02 - In a large mixing bowl, combine the trimmed Brussels sprouts, sliced apples, and red onion. Drizzle with olive oil, sprinkle with kosher salt and freshly ground black pepper. Toss until all components are evenly coated.
03 - Spread the seasoned vegetable and fruit mixture in a single, even layer onto the prepared sheet pan.
04 - Roast in the preheated oven for 20–25 minutes. Stir the contents once halfway through the roasting time, ensuring the Brussels sprouts achieve a golden hue and the apples become tender.
05 - While the vegetables and fruit are roasting, prepare the dressing. In a medium bowl, whisk together the mayonnaise, sour cream, dill pickle juice, chopped dill pickles, fresh dill, chives, garlic powder, onion powder, and black pepper until the mixture is smooth. Season with salt to your preference.
06 - Transfer the roasted Brussels sprouts and apples to a serving platter. Generously drizzle the dill pickle ranch dressing over the roasted components.
07 - If desired, garnish with additional fresh dill. Serve the dish warm.