what to serve with chicken marbella?
I love it too (and it freezes well). I like it with an assertive green to cut the richness, something like broccoli rabe or kale. If we don't just have it with crusty bread, our grain choices are usually quinoa (I always dress quinoa with lemon, soy sauce and olive oil) or a long grain brown/wild rice mix. I'd bet on mashed potato/celeriac too.
Couscous has worked well for me, hot or at room temp. To serve hot, do it pilaf style - mince some onion and saute until golden, stir in some minced garlic and then the couscous, then use chicken stock as the liquid. Vary as you'd like (stir in some fresh herbs or toasted slivered almonds). To make ahead and serve room temp, cook in chicken stock then dress with a EVOO and lots of fresh lemon juice, plus minced green onion and fresh herbs.
With such a complex main course, I would stick with an uncomplicated green veg, and I tend to go with green beans if I don't know my guests tastes since most people will eat them. My standby is to whirl up some fresh breadcrumbs in the blender, lightly toast them in a saute pan in a generous amount of olive oil, add some finely smashed garlic and some fresh parsley, and sprinkle on top of thawed Trader Joe's haricot vert. I bake it for about 12-15 minutes depending on what the oven is set at for the other parts of the meal, until everything is hot and the crumbs are browned. Super easy and often requested.
If you'd rather do a salad, you might want to consider some greens topped with avocado, orange segments, red onion, pine nuts or sliced almonds and dressed with a sherry wine vinegarette.
Enjoy your party!