Rinse the quinoa under cold water to remove any bitterness. Add it to a saucepan with water or broth, then bring to a boil. Once boiling, reduce to a simmer, cover, and cook for about 15 minutes until the liquid is absorbed. Fluff with a fork and let it cool slightly.
Remove the thick stems from the kale leaves and chop the leaves into bite-sized pieces. Place them in a large bowl. Drizzle with a teaspoon of olive oil and a small pinch of salt, then massage the leaves with your hands for 2–3 minutes until they soften and turn darker green. This step makes the kale tender and more enjoyable to eat.
Dice the red bell pepper, slice the red onion thinly, and shred or grate the carrots. Keeping everything bite-sized helps the salad feel more cohesive and easy to enjoy.
Whisk together olive oil, Dijon mustard, honey, apple cider vinegar, garlic, salt, and pepper until smooth. Alternatively, place everything in a small jar, close the lid, and shake well until emulsified. Taste and adjust the seasoning to your liking.
In the large bowl with the kale, add quinoa, red bell pepper, carrots, red onion, cranberries, pumpkin seeds, and feta if using. Pour the dressing over the top. Gently toss everything together until evenly coated.
This salad can be served immediately, but it also tastes even better after resting for 15 minutes in the fridge so the flavors can mingle. Garnish with extra seeds or a sprinkle of cheese before serving.