01 - Preheat the oven to 400°F and line a baking sheet with parchment paper.
02 - Toss the cubed butternut squash with 2 tablespoons olive oil, 1/2 teaspoon salt, and 1/4 teaspoon black pepper; spread evenly on the prepared baking sheet.
03 - Roast for 25 to 30 minutes, turning once halfway through, until golden and fork-tender; allow to cool slightly.
04 - While the squash roasts, toast pecans in a dry skillet over medium heat for 3 to 4 minutes until fragrant; set aside.
05 - In a small bowl, whisk together olive oil, balsamic vinegar, maple syrup, Dijon mustard, salt, and black pepper until combined.
06 - In a large salad bowl, combine mixed greens, roasted butternut squash, sliced red onion, toasted pecans, and feta cheese if using.
07 - Drizzle the dressing over the salad and toss gently; serve immediately.