Wash the mustard greens thoroughly, cut into bite-sized pieces, and drain.

Sauté the shallot until fragrant, then add water and bring to a boil with the bouillon cube. Add the tofu, cut into cubes, and cook for 2 minutes.

Add the mustard greens and cook for another 1-2 minutes until just tender. Taste and adjust seasoning as needed.

Serve hot in a bowl, topped with freshly ground black pepper.