How to Make It
Heat the oil in a small saucepan over medium heat. Add the shallot, mustard seeds, ginger, garlic, and ¼ teaspoon each salt and pepper. Cook, stirring occasionally, until the shallot is soft, 3 to 5 minutes.
Add the tomato paste and cumin to the saucepan and cook, stirring, for 1 minute. Add the sugar and ½ cup water and stir to combine. Transfer to a small bowl and refrigerate until chilled, at least 1 hour. Fold in the cilantro and serve with the shrimp.