Instructions

• Start by heating the sesame oil and butter in a large pot over medium heat. Once melted, add the sliced onions and cook slowly, stirring often, until they soften and become slightly golden, about 8-10 minutes. This step builds that signature deep flavor.
• Add the garlic and ginger, stirring for about 1 minute until fragrant. If you're using mushrooms, add them now and cook for another 2-3 minutes until tender.
• Pour in the broth and bring everything to a gentle simmer. Stir in the soy sauce, salt, and pepper. Let the soup simmer uncovered for 15-20 minutes so all the flavors meld together beautifully.
• Taste and adjust seasoning if needed. The broth should be light but savory with a slightly sweet onion finish.
• Ladle into bowls and top with fresh green onions for that classic hibachi-style touch. Serve this Japanese onion soup hot as a starter or pair it with fried rice and grilled chicken for the full takeout-at-home experience.