Southwestern Corn Relish

Name: Southwestern Corn Relish
Ingredients: 600 g corn kernels (frozen or fresh. 4 cups / 1 US quart / 21 oz in weight); 750 ml tomatoes (diced. Drained from a can is fine. 3 cups / 24 oz); 150 g onion (chopped. 1 cup, 5 oz. 1 large); 250 g green bell pepper (seeded, chopped. 1 1/2 cups, 8 oz. 1 large); 125 g red bell pepper (seeded, chopped. 3/4 cup, 4 oz. 1 medium); 100 g sugar (white. 1/2 cup / 4 oz); 500 ml cider vinegar (cider vinegar, 5% acidity or higher. 2 cups / 16 oz); 1 tablespoon pickling salt; 2 tablespoons mustard seed; 1 teaspoon chile flakes (optional); liquid smoke (few drops, optional)