Preheat the oven to 400°F (200°C). Trim and wash the beets, then place them on a piece of aluminum foil. Drizzle with olive oil and season with salt and pepper. Wrap them tightly into a sealed packet to trap the steam—this helps them cook evenly and stay tender. Place on a tray and roast for 45–60 minutes, depending on size, until a knife slides in easily. Let them cool slightly, then rub off the skins using a towel. Cut into bite-sized cubes.
Spread the walnuts in a single layer on a baking tray. Place them in the oven and toast for about 5 minutes, until lightly golden and fragrant. Check them halfway through and give the tray a gentle shake—they should color evenly but not darken too much. Remove from the oven and let them cool completely to keep their texture.
In a large bowl, combine the greens with the roasted beets, toasted walnuts, cheese, and fresh herbs. Distribute everything evenly so each bite has contrast in flavor and texture.
Add the balsamic dressing just before serving to keep the leaves crisp. Toss gently so everything is lightly coated without bruising the greens. Serve immediately.
Notes
Roasting the beets Wrapping the beets in foil helps them steam gently while roasting, keeping them tender and concentrated in flavor. For a slightly deeper, more caramelized taste, you can open the foil for the last 10–15 minutes.
Even cooking Try to use beets of similar size so they cook at the same rate. Larger beets may need a bit more time.
Toasting the walnuts Keep a close eye on the walnuts in the oven—they can go from perfectly toasted to bitter quite quickly. Let them cool fully to maintain their crunch.
Assembling the salad Dress the salad just before serving to keep the greens fresh and crisp. If preparing ahead, keep all components separate and combine at the last moment.
Make it your own You can swap the cheese depending on what you have—goat cheese, feta, or a mild blue all work well with the beets and walnuts.