1. In a heavy 12-inch skillet, heat the oil over moderate heat until a light haze forms above it. Drop in the ham, garlic and chilies and, stirring constantly, cook for 2or 3minutes.
2. Add the tomatoes, tomato puree, chives, parsley, vinegar, salt and a few grindings of pepper.
3. Stirring frequently, cook briskly until most of the liquid in the pan has evaporated and the mixture is thick enough to hold its shape lightly in a spoon.
4. Stir in the palm hearts, reduce the heat to low, and simmer uncovered for about 3 to 4 minutes. Add the olives and capers and cook the "Palmito Guisado" for a minute or so longer to heat them through.
5. Taste for seasoning and serve at once, accompanied by a separate bowl of grated Parmesan cheese.
