Preheat the oven to 400°F. Place the butternut squash and garlic on a rimmed baking sheet, drizzle with about 2 tablespoons olive oil, season with salt and pepper, and toss well, using your hands to evenly coat the squash. Roast the squash in the oven for about 15-20 minutes, or until fork tender.
While the butternut squash and garlic roasts, place the farro and about 4-5 cups of cold water in a saucepan, season generously with kosher salt, and bring to a boil over medium high heat. Once the farro comes to a boil, lower heat to a simmer, cover, and let the farro cook for up to 40 minutes, or until the farro has bloomed. Check your farro package for instructions, as some farro may cook faster/longer.
When the butternut squash is tender, remove from the oven and set aside. Squeeze the garlic out of the peel into a small bowl, mash with a fork, and set aside. Discard garlic peel.
In a deep sided saute pan, heat remaining 2 tablespoons olive oil and butter over medium-low heat. Once the butter is melted, add the shallots and roasted garlic and cook for a minute or two, or until the shallots are translucent. Stir in the kale, butternut squash, and farro. Season to taste with salt and pepper. Remove from heat and let it sit while you make the cranberry dressing.
In a small bowl, whisk together the balsamic vinegar, salt and pepper. While whisking, slowly drizzle in the olive oil. Stir in about half of the dressing into the warm salad. Stir in the feta cheese.
Transfer the salad to a serving dish and serve warm, with additional dressing on the side.