In a large glass or ceramic bowl, combine the tomatoes, green onions and chilies; set aside.

In a small bowl, mix together black pepper, mustard seed, ginger, garlic, turmeric, cumin and paprika.

In a heavy-bottomed pot, such as a Le Creuset, heat the oil over medium-high heat. When oil looks wavy in appearance, add spice mixture and stir for 2-3 minutes over medium heat. Pour oil and spices over tomato mixture. 

Return the pan to the stove and over medium-high heat add the vinegar, brown sugar and salt. Bring to a low boil and stir. Pour the vinegar mixture over tomato mixture (it's ok if the vinegar is warm). Stir gently to combine and set aside.

When the tomatoes come to room temperature, cover and store in the refrigerator until ready to use. Tomatoes will keep, if sealed in an airtight container, 3-4 days.