Scrub the 1 pound live mussels under cold running water and discard any with broken shells or that remain open when tapped.
Heat a wok or sauté pan over medium-high heat and swirl in the 2 teaspoons cooking oil. Add the 1/2 diced onion and sauté for 2 minutes, until softened.
Add the 1 clove garlic (finely minced) and 1 teaspoon finely grated fresh ginger; cook, stirring, until fragrant, about 30 seconds.
Pour in the 2 cups vegetable broth, then add the 2 tablespoons Miso & Easy (or 1 tablespoon miso paste) and the 1 teaspoon hot chili sauce. Stir until the miso is dissolved into the broth. Increase heat until the liquid comes to a gentle simmer.
When the broth is simmering, add the 1 diced tomato, the handful of fresh leafy vegetable, and the cleaned mussels. Cover the pan and steam for 3 minutes, or until the mussels have opened.
Remove the lid, discard any mussels that have not opened, and serve immediately with the 2 lime wedges for squeezing over the mussels.