This tart-sweet relish, which makes use of a bumper crop of late-summer produce, is the perfect condiment for the Cod Cakes. This recipe is based on one in Simple Pleasures from Our Maritime Kitchens by Julie V. Watson (Raincoast Books, 2002).
1½ lbs. green tomatoes, cored and finely chopped 1 medium yellow onion, finely chopped 1 rib celery, finely chopped ½ green bell pepper, cored, seeded, and finely chopped ½ red bell pepper, cored, seeded, and finely chopped 2 tbsp. kosher salt ½ cup sugar ⅓ cup distilled white vinegar 1½ tsp. dry mustard 1½ tsp. yellow mustard seeds 1 tsp. celery seeds 1 tsp. crushed red chile flakes ¼ tsp. ground coriander
1. Toss tomatoes, onions, celery, and peppers in a large bowl with salt; cover with plastic wrap and let sit at room temperature for 4 hours or overnight. Transfer vegetables to a sieve and press to extract excess juices; discard juices.
2. Transfer vegetables to a 6-qt. saucepan and add remaining ingredients. Cover, bring mixture to a boil, reduce heat to medium-low, and simmer, stirring occasionally, until vegetables are very soft, about 2½ hours. Transfer relish to a jar and let cool. Cover and refrigerate for up to 2 weeks.