With the half and half you can make a white sauce. That can be served with your pork or chicken or with pasta.
To make a white sauce, chop some garlic finely. Add 2 tbsp of olive oil/butter in a pan, when it's hot, add garlic and saute it for a minute. Then add 2 tbsp of flour and let it roast in the oil and with the garlic on low heat for atleast 10 minutes or so. Add the half and half and some water if you want to thin it out a bit more.
You can serve it as a gravy with some freshly chopped parsley added to it or you can stir in some pasta in it and top it with parsley, lemon zest, lemon juice and some parmesean cheese. It's simple but delicious.
With the sour cream. You can make a marinade for the chicken. You can add the sour cream to a bowl, stir in some cumin powder, corrainder powder, chili powder, freshly chopped cilantro, some lime juice, salt and leave it for a couple of hours.
Put the chicken, sauce and all in a pan and let it cook until the chicken is done. It will have a nice gravy. Chop some more fresh cilantro and add it at the last minute and serve.