Delicious on just about anything,
In a wide saucepan, heat oil over medium heat. Add black mustard seed and cook until they start to pop.
Add cherry tomatoes, serrano chilies, ginger, and salt.
Stir, breaking down tomatoes with the back of the spoon. If tomatoes start to stick, turn heat down to a simmer. Cook until tomatoes are broken down, no longer than 1 hour.
Store for 1 week in the refrigerator, or in the freezer for up to 6 months.