Quinoa salad with apples and sweet potatoes

Spring actually is right around the corner, the weather notwithstanding, which makes me want to eat green, healthy things. However, the lettuces at the supermarket are still looking limp and tasteless, so I'm attempting a spring-like salad out of winter ingredients. To wit, this quinoa salad. I've made a quinoa salad with sweet potatoes before, but this one feels spring-ier to me.

Note: I'm not a huge fan of raw onion, so I left it out and used scallions instead.

From Food and Wine:

1/2 cup extra-virgin olive oil
1 1/2 cups quinoa
Salt
1 1/2 pounds sweet potatoes, peeled and cut into 3/4-inch dice
Freshly ground pepper
1/4 cup apple cider vinegar
2 large Granny Smith apples, cut into 1/2-inch dice
1/2 cup chopped flat-leaf parsley
1/2 medium red onion, thinly sliced
8 packed cups baby greens, such as arugula or kale (about 6 ounces)

Preheat the oven to 400°. In a large saucepan, heat 1 tablespoon of the olive oil. Add the quinoa and toast over moderate heat, stirring, for 2 minutes. Add 3 cups of water, season with salt and bring to a boil. Cover and simmer the quinoa for 16 minutes. Remove from the heat and let stand for 10 minutes. Fluff the quinoa, spread it out on a baking sheet and refrigerate until it is chilled, about 20 minutes.

Meanwhile, on a baking sheet, toss the sweet potatoes with 1 tablespoon of the olive oil and season with salt and pepper. Roast for about 25 minutes, stirring once, until golden and softened. Let cool.
In a large bowl, whisk the remaining 6 tablespoons of olive oil with the vinegar; season with salt and pepper. Add the quinoa, sweet potatoes, apples, parsley, onion and greens and toss well. Serve right away.