In a 25 centimeter / 10 inch skillet, warm the oil, add the onion, cover, and cook 5 minutes, or until the onion is soft and golden. Remove from the heat. Tilt into a mixing bowl. Add the rice, chickpeas, tomatoes, salt, aleppo pepper, spices, parsley, mint, and sugar; mix well. Makes about 3 1/2 cups filling.
Rinse and drain the swiss chard leaves. Remove the stalks from the greens and reserve a few for later. Dip the leaves into simmering water until pliable, about 10 seconds, and refresh in a basin of cold water. Drain, then gently press out excess moisture. Place the leaves, shiny side down and a few at a time, on a work surface. If the leaves are very large, halve them lengthwise, removing the center rib. Trim each leaf to make an approximate 12.5 centimeter / 5 inch square (the ribs should be horizontal, not vertical, for easier rolling).
Place a heaping teaspoon of filling below the rib of each leaf. Fold over the filling and roll up to make a firm, thin cigarette shape. If necessary, squeeze gently in the palm of your hand to firm the roll up. Repeat with the remaining leaves and filling.
Line a 1 liter / 1 quart heavy saucepan with a few diced stalks. Place the stuffed leaves, open ends down, in tightly packed rows and criss-crossing layers. Weight them down with a plate just large enough to fit inside the saucepan.
Pour the water down the inside of the saucepan. Bring to a boil; boil hard for half a minute, cover with a tight-fitting lid, reduce the heat to low, and cook 40 minutes. Remove from the heat and let stand 20 minutes before uncovering. Add the lemon juice to the pan juices and swirl to combine. Serve warm or cold, garnished with lemon wedges.
You can substitute tender grape leaves for the swiss chard, but you'll need to cook the rolls an extra 20 to 30 minutes.
When eastern mediterranean cooks have lots of time, they will often skin chickpeas for certain dishes, not only to get rid of the starchy skin, which is somewhat indigestible, but also to achieve a glistening appearance. In nearly all the recipes in this book, I have opted to leave the skins on. This recipe is one of the exceptions. Here the chickpeas must be peeled and halved so that they will cook as quickly as the other ingredients. The extra effort is worthwhile, because peeled chickpeas provide a unique taste and texture, and only a handful is needed for the dish. To peel chickpeas easily: place soaked and uncooked chickpeas on a kitchen towel, cover with another towel, then gently hit each pea with a rolling pin; rub the peas; the peels will come right off and the pea will split in two.