In a small measuring cup add hot water and black beans, let this soak while you prepare the rest of the ingredients.
In a small pan sauté the ginger and garlic with the oil until fragrant and the edges of the garlic is starting to brown.
Add the sriracha paste followed by the soaked black beans and their soaking liquid.
Add the soy sauce and rice wine vinegar, let this mixture come to a low simmer and add the block of silken tofu.
Simmer the block of tofu for 8 minutes spooning sauce over the top occasionally, gently flip the tofu half way through cooking, it can be helpful to cut the block in half or quarters depending on its size.
When finished cooking garnish the tofu with chopped green onions and serve with rice.