Preheat the oven to 400 degrees.
Make a cut right above the top of the beet to separate the stems from the beet. Wrap each beet in parchment paper and arrange them on a large sheet pan. Bake the beets for 50-60 minutes (depending on their size) or until tender. Check the beets every 20 minutes to make sure they're not burning on the side they're resting on. If they seem dry, add a drizzle of water over the beet.
While the beets are roasting, cut the greens into 1-inch strips, cut the stems into 2-inch pieces and quarter the onions. Arrange the onion wedges (don't separate the slices) and beet stems on a large parchment-lined sheet pan. Drizzle 2 tbsp of balsamic vinegar over the onions (this is what helps the onions to caramelize!) and stems. Season with a ¼ tsp salt and ¼ tsp black pepper. Cover with parchment paper and bake for 20 minutes. Remove the parchment and let it cook for 10-15 more minutes or until tender.
Next, put the sliced beet greens in a large pan over medium heat with a little bit of water to help soften the greens. Season with ¼ tsp of garlic powder, ¼ tsp of onion powder, and a pinch of salt and pepper. Let the greens cook for 5-6 minutes or until they start to wilt.
The beets are done roasting when you can stick a knife easily into the beet. Let the beets cool for 5-10 minutes or until they are cool enough to handle. Cut off the top and the pointy end of each beet.
Put a paper towel in one of your hands and put the beet on top of the paper towel. Hold another paper towel in your other hand and use it to gently rub the skin off. If the skin doesn’t easily peel off, it needs to be cooked longer. Slice each beet into ½-inch slices and then cut each slice in half.
On a large platter, lay the beet greens down first and then arrange the beet slices, onion wedges, and beet stems in a decorative pattern on top of the greens.
Crumble the vegan feta cheese over the vegetables and then drizzle 2-3 tbsp of balsamic glaze right before you serve.