Finely chop the onions. Core, seed, and chop or thinly slice the peppers. Cut the ham into small cubes.
Heat the oil in a medium-size casserole or a deep, large skillet over medium heat. Add the onions, reduce the heat to medium, and sauté until translucent, about 5 minutes.
Add the peppers, cover, and simmer gently until the peppers are somewhat tender, about 5 minutes more. Add all the remaining ingredients except for the parsley and season to taste with salt and pepper. Cook covered over low heat until the ingredients are tender and hot, 10 to 15 minutes.
Meanwhile chop the parsley. When the stew is done, stir in the parsley, adjust the seasoning, and serve.