In a food processor, combine the cumin, tomato, cilantro, ginger, and chiles. Turns out, I had a really big tomato and so it mostly tinted the curry paste red, but the recipe was originally green curry based, so hence the subjective coloring. Set mixture aside.
Heat dutch oven under medium high heat and add oil. When oil is shimmering and hot, add onions and cook until soft and translucent, about 5 minutes or so. Add the curry paste and cook for about 5 minutes longer. Add in coconut milk and stir. If too thick, add water to thin mixture out. Season with salt and pepper to taste.
Bring mixture to a boil and add mussels. Mix well, making sure mussels are well coated with curry sauce. Cover mixture, lower heat to a simmer, and steam mussels for about 5 minutes, or until all of the shells have opened. Discard any shells that have not opened.
Serve in a large bowl with pieces of a nice baguette.