Have a large oven safe serving dish near the stove. Heat a heavy duty pan over medium high heat, add about 1 tbsp of olive oil, and place 3-4 pieces of chicken in the pan. Do not crowd. Cook for about 2 minutes on each side, and remove to the serving dish (NOTE: you do not need to cook it all the way through, it will cook as it sits). Repeat with more oil and more chicken until all the chicken is browned.

Add remaining oil to the pan, add the mushrooms, a pinch of pepper and sauté until shrunken, and browned, and remove them from the pan and add them to the dish with the chicken.

Add the garlic to the pan, and cook until lightly browned. Add the tomatoes, season with a pinch of pepper, add the spinach, and sauté until wilted. Add this mixture to the dish with the chicken.

Add the wine to the pan, let reduce for a minute, scraping up any brown bits at the bottom of the pan and add the chicken stock. Let cook for 3-5 minutes (it should boil), and add the lemon juice. Pour this mixture over the chicken and arrange the vegetables around the chicken in a presentable way. Serve right away or cool and refrigerate covered overnight. Let come to room temperature for at least one hour before reheating and then reheat in a 300-400˚F oven (depending on what else is in the oven) until heated through, about 30 minutes.