Heat a large skillet over medium heat and add the butter. Once the butter is melted, add the shallots and apples. Cook, stirring occasionally, until the shallots are beginning to caramelize and the apples are tender, about 15 minutes.
Preheat the oven to 425 degrees Fahrenheit and line a large baking sheet with parchment paper.
Arrange the brussels sprouts in a single layer on the baking sheet and drizzle with avocado oil. Sprinkle with minced garlic and season with salt and pepper. Toss to coat. Add the caramelized shallot and apple to the sheet among the brussels sprouts.
Transfer the baking sheet to the preheated oven and roast, stirring once, for approximately 15-20 minutes, until brussels sprouts are cooked through and beginning to crisp. Turn the oven to broil and broil brussels sprouts for 2 minutes for an extra char and crispy edges. Serve immediately.
Try adding a sprinkle of freshly cooked & chopped bacon for a salty finishing touch.
Use vegan butter or avocado oil in place of the butter for a vegan version.