Savory Japchae with Sweet Potato Noodles and Beef

Ingredients

• 900 g thinly sliced beef (or substitute with chicken, tofu, or shrimp)
• 450 g Korean sweet potato glass noodles
• 3 medium carrots, julienned
• 1 large white onion, thinly sliced
• 1/2 bunch green onions, chopped
• 225 g spinach leaves
• 6 garlic cloves, minced
• 4 tablespoons sesame oil, divided
• 1 tablespoon olive oil
• 6 tablespoons soy sauce (or tamari for gluten-free option)
• 3 tablespoons brown sugar