Preheat your oven to 400°F (200°C). Place the sliced garlic bulb on a small piece of aluminum foil, drizzle with olive oil, and wrap it tightly. Roast for 30-40 minutes, or until the garlic is soft and golden brown. Once roasted, let it cool slightly, then carefully squeeze out the softened garlic cloves into a small bowl. Mash them with a fork until smooth.

In a medium saucepan, heat the vegetable broth over medium heat. If using ginger, add the grated ginger to the broth now and let it simmer for about 5 minutes to infuse its flavor.

In a separate small bowl, combine the miso paste, soy sauce, and sesame oil. Add about ½ cup of the warm broth to this mixture and whisk until the miso paste is fully dissolved and smooth. This prevents the miso from clumping in the soup.

Pour the miso mixture into the simmering broth in the saucepan. Stir well to combine.

Add the mashed roasted garlic to the soup. Stir gently until the roasted garlic is completely incorporated, lending its sweet, mellow flavor to the broth.

Reduce the heat to low. Gently heat the soup for another 5-10 minutes, ensuring it doesn't boil after the miso has been added, as boiling can diminish its beneficial probiotics and delicate flavor.

Ladle the hot soup into bowls. Garnish generously with your favorite toppings such as thinly sliced green onions, a sprinkle of toasted sesame seeds, a few silken tofu cubes, or a swirl of chili oil for a touch of heat. Enjoy immediately!