Preheat the oven to 425°F (220°C). Line a large rimmed baking sheet with parchment paper, if desired.

Halve the squash lengthwise, scoop out the seeds, peel, and cut into even 3/4-inch-thick wedges or crescent-shaped pieces.

In a large bowl, toss the squash with 2 tablespoons olive oil, maple syrup, smoked paprika, 3/4 teaspoon salt, and black pepper until evenly coated.

Spread squash in a single layer with space between pieces. Roast for 30–35 minutes, flipping once around the 20-minute mark, until deeply golden at the edges and tender when pierced with a fork.

Meanwhile, toast the walnuts in a dry skillet over medium-low heat for 3–5 minutes, stirring frequently. Transfer to a plate and cool briefly.

Add toasted walnuts, sage, parsley, Parmesan, garlic, lemon juice, and 1/4 teaspoon salt to a food processor. Pulse until finely chopped.

With the machine running in short bursts, stream in 1/3 cup extra-virgin olive oil and pulse to a spoonable pesto. Add 1–2 tablespoons cold water if a looser consistency is preferred. Taste and adjust lemon or salt.

Arrange hot squash on a serving platter. Spoon or drizzle sage pesto over the wedges, add optional pomegranate arils, and serve with remaining pesto on the side.