Made chicken and olives tagine last night. Gonna try it again tonight with lamb shank, lemon, olives, and dried apricots.
Puree two tomatoes and an onion with a healthy pinch of saffron paprika and ginger powder, and some salt/pepper. Add 1/4c olive oil and 1/4c melted butter, and marinade a chicken's worth of chicken parts in the whole mess for a half hour.
Put the chicken and marinade into a tagine and add a cup or two of chicken broth to mostly cover the chicken. Simmer at medium-low heat for an hour or two, until the chicken is cooked through. Add 1-1/2 cups of pitted olives and the chopped peel from two preserved lemons (optional) and simmer another half hour.
If you use a skillet or saute pan, you might need to add more water during the simmer, but then you can raise the heat at the end and reduce the sauce to make it thicker. Present tableside in the tagine or plate with flatbread and freshly minced coriander.