Step 1

Preheat oven to 425 degrees F.

Step 2

Toss sweet potatoes, 1 tablespoon oil, 1/4 teaspoon pepper and 1/8 teaspoon salt together in a large bowl. Transfer to a large rimmed baking sheet and roast, stirring once, until tender, 15 to 18 minutes. Let cool for at least 10 minutes.

Step 3

Meanwhile, place basil, the remaining 1/4 cup oil, vinegar, shallot, mustard and the remaining 1/4 teaspoon pepper and 1/8 teaspoon salt in a mini food processor. Process until mostly smooth. Transfer to the large bowl. Add spinach, beans, cabbage, bell pepper, pecans and the cooled sweet potatoes. Toss to coat.