Sweet Potato and Kale Pizza

INGREDIENTS

• 2 tablespoons shredded Parmesan
• 1/8 teaspoon crushed red pepper flakes
• 1 1/2 tablespoons olive oil, divided
• 1 medium sweet potato, peeled and cut into 1/2-inch cubes
• 1/4 cup crumbled goat cheese
• 1 tablespoon crushed walnuts
• 1 package (21 ounces) prepared whole-wheat pizza dough
• 1 bunch curly kale, stemmed and torn into bite-size pieces