South Indian Tomato Chutney

6 cups chopped, seeded tomatoes (about 6 large tomatoes)

8 garlic cloves, peeled and smashed

2 tablespoons canola oil

1 tablespoon tamarind paste

2 teaspoons brown mustard seeds

2 teaspoons cumin seeds

1 teaspoon fenugreek seeds

1 teaspoon demerara sugar

3 dried red chiles (such as Guntur), seeded and broken into pieces (Optional)

Cooking spray

⅞ teaspoon kosher salt