Prepare the Oven and Beets: Preheat your oven to 400°F (200°C). Rinse the beets thoroughly to remove any dirt. Wrap each beet individually in aluminum foil, then drizzle a generous amount of extra-virgin olive oil over the foil-wrapped beets. Sprinkle lightly with salt and freshly ground pepper to season. Place the wrapped beets on a baking tray, ensuring they have enough space to roast evenly.
Roast the Beets Until Tender: Put the baking tray in the preheated oven and roast the beets for 40 to 90 minutes, depending on their size. You’ll know they’re done when a fork easily pierces the beets, indicating softness. Once cooked, carefully remove them from the oven and allow them to cool enough to handle.
Peel and Slice the Beets: After the beets have cooled, unwrap them and gently rub off their skins using your hands under running water. The skins should slide off easily. Slice the peeled beets into approximately ¼-inch thick rounds for a perfect salad texture.
Assemble the Salad Components: On a large serving plate or bowl, arrange the salad greens as a base. Evenly distribute the sliced shallots and green apple over the greens. Layer the beet slices on top, followed by toasted walnuts and crumbled goat cheese. If using, sprinkle microgreens for a fresh, decorative touch.
Dress and Serve: Drizzle the salad generously with your favorite balsamic vinaigrette. Finish by seasoning with flaky sea salt and freshly ground black pepper to enhance all the flavors. Serve immediately for the best freshness and texture.