Step 1: Prepare the Vegetables

1. Preheat the Oven: Preheat your oven to 400°F (200°C).
2. Cube the Beets and Sweet Potatoes: Peel the beets and sweet potatoes, then cut them into 1-inch cubes. Try to keep the pieces uniform for even cooking.
3. Season and Roast: On a baking sheet lined with parchment paper, spread out the beets and sweet potatoes in a single layer. Drizzle with 2 tablespoons of olive oil, and season with salt and black pepper. Toss well to coat evenly.
4. Roast: Roast in the oven for 30-40 minutes, turning the vegetables halfway through, until they are fork-tender and slightly caramelized. Remove from the oven and let them cool slightly.

Step 2: Make the Honey Dijon Dressing

1. Mix Ingredients: In a small bowl or a mason jar, combine the extra-virgin olive oil, Dijon mustard, honey, apple cider vinegar, and minced garlic (if using). Whisk vigorously or shake the jar until the dressing emulsifies and becomes smooth.
2. Season: Taste and add salt and pepper as needed. Adjust the sweetness or acidity to your liking by adding more honey or vinegar.

Step 3: Toast the Pine Nuts

1. Toast the Pine Nuts: Place the pine nuts in a small, dry skillet over medium-low heat. Stir frequently until the pine nuts are golden brown and fragrant, about 3-5 minutes. Be careful not to burn them. Once toasted, remove from the heat and set aside.

Step 4: Assemble the Salad

1. Layer the Greens: In a large salad bowl or a serving platter, spread the mixed salad greens as the base.
2. Add the Roasted Vegetables: Arrange the roasted beets and sweet potatoes over the greens.
3. Sprinkle with Feta and Pine Nuts: If using feta, sprinkle it over the salad along with the toasted pine nuts.
4. Drizzle with Dressing: Pour the Honey Dijon Dressing over the salad just before serving. Toss gently to combine, or leave the salad deconstructed for a more elegant presentation.
5. Garnish: Finish with chopped fresh parsley or microgreens for a burst of color and freshness.