Sweet Potato Noodles Japchae

Name: Sweet Potato Noodles (Japchae)
Ingredients: 8 ounces sweet potato noodles; 1/2 bunch spinach (about 4 ounces), rinsed and trimmed; 2 cloves garlic, minced; 1 tablespoon plus 1 1/2 teaspoons Asian sesame oil; 1/4 teaspoon salt; 1 tablespoon vegetable oil; 6 ounces beef rib-eye, cut into 1/4- to 1/2-inch-thick strips; 1/4 cup plus 1 teaspoon soy sauce; 1/4 medium onion, sliced; 3 to 4 pyongo or shiitake mushrooms, sliced; 1 carrot, shredded or cut into thin strips; 3 green onions, cut into 1-inch pieces; 1/4 cup sugar; Toasted sesame seeds for garnish