Preheat your oven to 450ºF and line a half sheet pan with parchment paper.
Toss the sweet potatoes and brussels sprouts with the olive oil before seasoning with salt, pepper, cumin, and allspice.
Pour the veggies on the sheet pan in an even layer and bake for 25-35 minutes until they're fork tender and slightly browning around the edges.
In the last 10-15 minutes of baking the veggies, mix the butter, syrup, balsamic vinegar, water, and spices together in a small bowl. Set aside.
Heat a large skillet over medium-high heat. Once hot, cook the ground beef on one side for 3-4 minutes until a brown crust forms. Break the beef apart and fully cook.
Add the butter mixture to the pan and cook until the garlic is fragrant and the sauce thickens, about 1-2 minutes. Remove from the heat and serve over the spring mix with the roasted vegetables and goat cheese.
Optional: Add a drizzle of maple syrup or honey and a pinch of chile flakes alongside pickled beets (trust me).