Heat oil in a 12-inch non-stick skillet that has a lid. Over medium heat, saute onion for 5 minutes, stirring occasionally, until it softens and begins to color. During the last minute or so of that cooking time, add garlic, curry powder and pinch of sugar (less than 1/4 teaspoon), and cook and stir for another minute. The curry will become very fragrant.
Rinse chard in a colander and drain (you want some water clinging to the leaves), and then add to the skillet. Put the lid on, and after a minute or so, when chard has wilted slightly, turn and stir chard until it is combined with the onion mixture. Replace lid and cook for about 10 minutes, checking once or twice to stir and make sure it isnt sticking to the pan. If it is sticking, add 1-2 tablespoons of water and replace lid and continue cooking.
After the chard has been cooking for 10 minutes or is tender to your liking, add the beans and stir gently to combine and heat through. Pass the bottle of hot pepper sauce for those who like their curries a bit hotter.