Roast the Beets: Preheat your oven to 400°F (200°C). Wrap each beet individually in aluminum foil and place them on a baking sheet. Roast in the oven for 1 to 1.5 hours, or until tender when pierced with a knife. Once done, remove from the oven, let them cool slightly, then peel and cut into wedges.

Toast the Walnuts: While the beets are roasting, heat a dry skillet over medium heat. Add the walnut halves and toast them until they become fragrant, stirring occasionally to prevent burning. Once toasted, remove from heat and set aside.

Prepare the Vinaigrette: In a small bowl, whisk together the extra virgin olive oil, balsamic vinegar, Dijon mustard, and minced shallot. Season with salt and freshly ground black pepper to taste.

Assemble the Salad: On a large serving platter or individual plates, arrange the mixed salad greens. Top with the roasted beet wedges, crumbled goat cheese, and toasted walnuts. Drizzle the vinaigrette over the salad just before serving.