Sweet Potato Risotto with Spicy Maple Glazed Walnuts

Name: Sweet Potato Risotto with Spicy Maple Glazed Walnuts
Ingredients: 1 cup chopped walnuts; 1/4 teaspoon kosher salt; 1/4 teaspoon cayenne pepper; 1/8 teaspoon black pepper; 4 tablespoons real maple syrup; 4 cups peeled, diced sweet potatoes; 2 tablespoons olive oil, divided; 6 cups vegetable broth; 1 tablespoon butter; 1 medium onion, chopped; 1 cup carnaroli or arborio rice; 1 tablespoon finely chopped fresh rosemary; 1/4 cup real maple syrup; kosher salt, to taste; white pepper, to taste