Chicken with Lemon, Capers, and Mushrooms

(adapted from Dr. Atkins' Quick and Easy New Diet Cookbook by Robert and Veronica Atkins)

2 T olive oil
1 1/2 lb chicken breasts, cut into about 1/2" slices
12 oz mushrooms, cut into halves or quarters (depending on their size)
5 oz white cooking wine  (original recipe called for 2/3 c, but I only had 5 oz left, and it was fine)
zest from half a lemon
juice from half a lemon
2 T capers (drained)
salt and pepper to taste
3 T butter

1.  Heat the oil in a large, heavy skillet or dutch oven over medium (to medium-high) heat until hot but not smoking.  Add the chicken and cook, turning once, for 3-4 minutes on each side, or until browned.  (I had to do this in two batches, since my dutch oven is big, but not huge, and the original recipe might have expected the pieces to be thicker.)  Transfer chicken to a plate and keep warm.  (I put a piece of foil over it.)
2.  Add the mushrooms, wine, lemon zest, lemon juice, and capers to the pan.  Stir it around so the mushrooms are coated, and bring the liquid to a boil, scraping up any browned bits from the bottom of the pan.  Simmer for another 2 minutes or so.  Add some salt and pepper.  Add the butter and cook over low heat for 1 minute.  Return the chicken to the pan to heat through.

The book says this is 4 servings.  The two of us ate about 2/3 of this for lunch, along with Brussels sprouts.