Remove and discard thick stems from Swiss chard. Coarsely chop leaves (you should have about 12 cups); set aside. In a 4- to 5-quart Dutch oven cook onion, garlic, salt, black pepper, and crushed red pepper in hot oil over medium heat about 5 minutes or until onion is tender, stirring occasionally. Add Swiss chard and the water. Cook for 5 to 7 minutes or until chard is tender. Stir in currants and lemon juice. Cook for 3 minutes more.
Using a slotted spoon, transfer chard and currants to serving bowls; discard cooking liquid. Top each serving with almonds.