Swiss chard (about 4.5 lbs or 2 kg) • Water for boiling • potatoes, sliced into rounds • tomatoes, sliced into rounds • short-grain rice (about 300 grams) • (about 450 grams) tomatoes, finely chopped • onions, finely chopped • parsley, finely chopped • fresh mint • sumac • fresh lemon juice, or more to taste • salt •