Preheat the oven to 425F and line a baking sheet with parchment paper. Peel the beets and cut into 1-inch pieces. Toss the beet pieces with 1 tbsp of olive oil.
Put the beets on a baking sheet in a single layer, put in the oven and bake for 30 minutes.
Make the dressing. Put balsamic vinegar, 2 tbsp extra-virgin olive oil, salt and pepper in a cup and mix with a fork.
Make the salad. Put roasted beets, oranges and parsley in a bowl. Pour the dressing over the beet salad and toss until combined. Sprinkle with feta cheese.