In a medium saucepan, bring rice and 1½ cups water to a boil over medium-high heat. Cover, and reduce heat to low. Simmer 18 minutes. Remove from heat, and let stand 10 minutes, covered, to allow rice to finish cooking. Fluff rice with a fork.
In a large bowl, combine rice, ham, tomatoes, parsley, onions, jalapeno, vinegar, olive oil, mustard, salt and pepper. Stir well, breaking up any clumps of rice. Season to taste with additional salt, pepper or vinegar, if desired.