Preheat your oven to 400°F (200°C). Place the diced sweet potatoes on a baking sheet, drizzle with olive oil, and season with salt and pepper. Toss to coat evenly.
Roast in the preheated oven for 25-30 minutes or until they are tender and slightly caramelized. Remove from the oven and set aside to cool.
Rinse the quinoa under cold water. In a medium saucepan, bring 1 cup of vegetable stock to a boil Add the quinoa, reduce the heat to low, cover, and simmer for 15-20 minutes or until the quinoa is cooked and the liquid is absorbed. Fluff the quinoa with a fork and allow it to cool.
In a large salad bowl, combine the roasted sweet potatoes, cooked quinoa, chopped kale (massage the chopped kale beforehand to make it more tender), dried cranberries, and chopped pecans or walnuts (if using). Toss gently to mix the ingredients evenly.
In a small bowl, whisk together the extra-virgin olive oil, apple cider vinegar, maple syrup, Dijon mustard, minced garlic, salt, and pepper until well combined.
Pour the apple cider vinaigrette over the salad and toss to coat everything with the dressing. Adjust the seasoning with salt and pepper, if needed. Serve chilled