How to Make It
Preheat the oven to 425°. Line a baking sheet with foil. In a small bowl, whisk together the vinegar, mustard and 3 tablespoons of the olive oil for the dressing. Season with salt and pepper and set aside.
Combine the squash, shallots and 2 tablespoons of olive oil in a medium bowl and toss to combine, then season to taste with salt and pepper.
Spread the squash and shallots on a single layer on a baking sheet and roast, turning occasionally, until the squash and shallots are tender and lightly golden, about 30 minutes. Remove from the oven and place directly into a large bowl.
Add the kale and dressing to the squash and shallots. Toss thoroughly, then place the mixture in a serving bowl, top with the feta cheese, and serve.