In a medium pot, pour in about 4 cups of vegetable broth and set it over medium heat. Allow the broth to warm gently for about 5 minutes until it starts to steam but does not boil.

Once the broth is warm, add 1-2 tablespoons of freshly grated ginger and optional minced garlic (1-2 cloves) to the pot. Sauté these ingredients for about 2 minutes, stirring frequently.

Lower the heat slightly and stir in 3 tablespoons of miso paste into the pot. Mix it until it fully dissolves into the broth, which should take about 1-2 minutes.

Next, squeeze in the juice of one fresh lemon (about 2 tablespoons). Stir gently and allow it to come to a gentle simmer for about 3-4 minutes.

Ladle the warm soup into bowls and garnish each bowl with sliced green onions. Serve hot.