Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or aluminum foil for easier cleanup.
Prep the beets. Trim the tops and bottoms of the beets, then scrub them clean. No need to peel them before roasting—the skins will slip right off after they're cooked. If your beets are large, cut them in half or quarters.
Season and wrap. Place the beets on your prepared baking sheet. Drizzle with olive oil and sprinkle with salt and pepper. If using foil, you can create individual packets for the beets (especially helpful if using different colored beets to prevent bleeding).
Roast until tender, about 45-60 minutes depending on size. You'll know they're done when a knife slides in easily. Let them cool until you can handle them comfortably.
Peel and slice. Once cooled, the skins should slip off easily using your hands or a paper towel (warning: your hands will get stained if using red beets—embrace your temporary tie-dye look or wear gloves). Slice the peeled beets into wedges or cubes, then drizzle with a little balsamic vinegar if desired. These can be made up to 3 days ahead and refrigerated.
Make the dressing. Combine all dressing ingredients in a jar, seal tightly, and shake vigorously until emulsified. Alternatively, whisk everything together in a small bowl. Taste and adjust seasoning.
Toast the nuts in a dry skillet over medium heat until fragrant and lightly browned, about 5 minutes, watching carefully so they don't burn. Let cool, then roughly chop.
Assemble the salad. In a large bowl, place your greens and drizzle with about half the dressing. Toss gently to coat. Transfer to a serving platter or individual plates.
Arrange with artistic flair. Top the dressed greens with the roasted beets, crumbled goat cheese, toasted nuts, red onion, and any optional add-ins. Sprinkle with fresh herbs.
Finish like a pro. Drizzle the remaining dressing over the top, focusing on the beets. Add a final crack of black pepper and serve immediately.