Preheat the oven to 400°F.
In a large bowl, combine all the ingredients for the meatballs. Form into small golf-sized balls (you should get 24-26), and arrange them about 1 inch apart on a parchment-lined baking sheet.
Bake for 15-20 minutes. Check temperature.
Make the sauce: combine tomato sauce and paste – set aside.
Heat the oil over high heat in a large cast iron pan until smoking. Add the mustard seeds and cover immediately, and wait until they stop popping (15 seconds). Turn the heat to medium-low and add the shallots, garlic, and ginger. Cook for 3-5 minutes, stirring nearly constantly, until the shallots are quite golden. Add the cumin, coriander, and cayenne, and cook for another minute or so, to toast the spices. Pour in tomato mixture, and cook down for 3-4 minutes. It should be reduced to an almost paste-like consistency.
Pour in the coconut milk (add more as needed), and about 1/4 cup of water. Bring to a boil.
Simmer covered for 5-10 minutes, to let the flavors meld. Taste for salt and spiciness.
Add the meatballs to the sauce. Toss well, heat the meatballs through, and serve.