Separate leaves from the stems of the Swiss chard. Roughly chop leaves, and set aside. Cut stems into 1-inch pieces.
In a large skillet or Dutch oven, heat olive oil over medium heat. Add onion, garlic, and jalapeno, and saute until onion is translucent, about 6 minutes. Add Swiss chard stems, olives, and the water; cover, and cook 3 minutes. Stir in Swiss chard leaves; cover, and continue cooking until stems and leaves are tender, about 4 minutes. Serve immediately.