Preheat the oven to 400 degrees F.
In a large bowl, whisk together 1 tablespoon olive oil, maple syrup, 1/2 teaspoon kosher salt and 1/4 teaspoon black pepper. Stir in the squash, coating it in the mixture.
Arrange the squash in a single layer on a sheet pan.
Roast the squash for 25-30 minutes, flipping halfway through roasting, until it is tender and lightly browned at the edges.
While the squash is roasting, make the couscous. Heat 1 tablespoon olive oil in a large saucepan over medium heat. Toast the couscous until it is golden, about 5 minutes. Add the water and bring to a boil. Reduce heat to low, cover and simmer until the water is absorbed and the couscous is tender, about 10 minutes.
For the pesto, puree the garlic, parsley, 1/4 cup chopped walnuts, Parmesan, lemon juice, 1/4 teaspoon salt and 1/4 teaspoon black pepper in a food processor. Finely chop the ingredients. With the motor is running, pour 1/3 cup olive oil through the feeder tube until the pesto is fully combined.
In a large bowl, stir the pesto into the couscous. Fold in the roasted squash, pomegranate seeds, 1/4 cup chopped walnuts and chives.