Once the shallot is translucent (3-4 minutes), add in the tomato sauce and stir. Bring this to a boil and then lower to a simmer. Cook for 15 minutes.
Add in the ham and the half and half to the sauce. The sauce will start to lighten in color. Turn the heat off and work the Greek yogurt into the sauce, stirring until it is fully incorporated. Finally, mix in most of the fresh parsley (save some to top your pasta!)