How to Make It
In a blender, puree the diced tomatoes. In a medium saucepan, heat the 2 tablespoons of oil until shimmering. Add the tomato puree and cook over moderately high heat, stirring frequently, until very thick, about 7 minutes. Add the Salsa Negra and 1/3 cup of water and simmer until slightly thickened, about 10 minutes. Season with salt and pepper.
Light a grill or preheat a grill pan. Brush the shrimp with oil and season with salt and pepper. Grill over moderately high heat, turning once, until lightly charred and cooked through, about 5 minutes. Drizzle the shrimp with the sauce, sprinkle with cilantro and serve.