Combine vinegar, sugar, and salt in a mason jar (or medium bowl).
Microwave for 45 to 60 seconds, or until hot. Stir until sugar and salt are dissolved.
Add onions to jar (or bowl), then press down to submerge in liquid. Cover and set aside.
Prepare Quinoa:
Combine quinoa, 2 cups water, and 1 teaspoon salt in a medium pot over high heat.
Bring to a boil, then cover pot and reduce heat to low. Cook for 15 to 18 minutes, or until water is absorbed and quinoa is tender.
Remove from heat, then fluff with a fork. Set aside to cool slightly before using.
Prepare Roasted Pumpkin:
Once quinoa starts cooking, place chopped pumpkin on a large baking sheet. Drizzle with olive oil, then sprinkle with cumin, cinnamon, and ginger. Season generously with salt and a few grinds pepper. Mix well.
Roast pumpkin for 40 minutes (or until browned and tender), flipping halfway through. Set aside to cool slightly.
Prepare Dressing:
Combine olive oil, lemon juice, shallot, maple syrup, mustard, salt, and pepper in a mason jar (or small bowl).
Cover jar, then shake ingredients together (or whisk, if using a bowl) until the dressing is thickened and looks creamy.
Assemble Salad:
Add ½ cup pickled onions (drained), quinoa, pumpkin, feta, pepitas, parsley, and mint in a large bowl.
Drizzle ½ the dressing over the salad, then mix well. Season with salt and pepper to taste, and add extra dressing, if desired (you will have leftovers).
Gently mix in arugula, then serve. Enjoy!
Notes
Pumpkin - Top prep the pumpkin, cut a small hole around the stem (so there is something to hold onto). Then use a vegetable peeler (or sharp paring knife) to peel the pumpkin. After it's peeled, cut the pumpkin in half and scoop out the seeds. Once the seeds are out, chop it into cubes.Leftover Dressing + Onions - You will have extra dressing and pickled onions. The dressing can be saved and used for other salads. Serve the pickled onions in other salads, bowls, tacos, and more.Timesavers - You can prepare the onions, dressing, quinoa, and pumpkin in advance. Then when it's time to serve the salad, just toss everything together.More Tips - Check out the info before this recipe card for helpful tips, variations, servings suggestions, and more!