Add the quinoa and water to a pot along with a pinch of salt. Bring to a boil, then reduce to a simmer, cover, and cook for 12-15 minutes, until the water is absorbed. Remove from heat, let sit for 5 minutes, then fluff with a fork. Set aside.

Preheat the oven to 400°F (200°C). Lightly spray the diced sweet potatoes with cooking spray and season with a pinch of salt and pepper. Spread them in an even layer on a baking sheet and roast for 25 minutes, flipping halfway through, until tender. Set aside.

Meanwhile, lightly spray a skillet with cooking spray and heat over medium heat. Add the ground beef, break it apart with a spoon, and cook for 8-10 minutes, until browned and cooked through. Season with salt and pepper and set aside.

In a small bowl, whisk together the Dijon mustard, apple cider vinegar, olive oil, and a pinch of salt and pepper to make a vinaigrette.

To serve, combine the quinoa, sweet potatoes, kale, feta, and ground beef, and drizzle with the vinaigrette. Alternatively, keep the components separate and assemble just before eating.

Meal Prep Tip: If making in bulk, store the beef, quinoa, vegetables, feta and vinaigrette separately in airtight containers in the refrigerator. Reheat and assemble just before serving.