Preheat the oven to 190c/375f. Place the chunks of sweet potato in a baking tin and drizzle on the olive oil. Sprinkle on the salt and pepper and toss everything together. Cook in the oven for 20-25 minutes until tender.
Whilst the potatoes are roasting, cook the quinoa according to the packet instructions, but also crumble in the stock cube for extra flavour. (For this amount of quinoa, I'd boil 360ml (1 1/2 cups) water, add the quinoa and stock cube, then cover and simmer for approx. 20 mins before fluffing with a fork.)
Whisk together the vinaigrette ingredients in a small bowl.
Place the warm quinoa, roasted sweet potato, pomegranate, goats cheese, and chopped herbs in a large bowl.
Toss everything together, then drizzle on the vinaigrette and serve.