1 Label the bag: Use a sharpie to write the date and the title of the recipe on a gallon-sized zip top bag so you can easily find it on SimplyRecipes.com when you want to cook it. Alternatively, write the cooking instructions on the bag.
2 Combine the ingredients: Roll down the opening of the bag a little just so you don’t accidently get raw chicken juices on the outside of the zip top. Add the chicken, spices, zest, lemon juice, garlic and olive oil.
Remove as much air as possible and seal the bag. Smoosh the chicken around so it’s coated in the marinade.
3 Lay the chicken flat in the freezer and freeze for up to 6 months.
Alternatively, you could skip the freezer and let it marinade in the fridge for a couple of hours and up to two days, then cook it according to the directions below.
4 Thaw the chicken before cooking: Take the chicken out of the freezer in the morning before you go to work, and it will be ready to cook by the end of the day.
5 Prepare the onion: Peel and trim the stem ends of the onion, but leave the stem intact so it can keep the onion layers together. Slice the onion in half. Then slice each half into 5 wedges leaving a little stem with each one.
6 Cook the chicken: Set a large skillet over medium heat add 2 teaspoons of olive oil. Once the oil shimmers, add chicken and any marinade in the bag. If any chicken is folded up, unfolded it so it lays flat in the pan. Cook the chicken for 2 minutes, then flip it.
7 Add the vegetables: Add the onion wedges, tomatoes, and capers. Cover with a lid. Let everything simmer together for 12 to 15 minutes. The tomatoes should be soft, and the onions dull in color.
8 Check the chicken: Check the chicken to see if it’s cooked through by cutting a piece open. If the juices run clear, and you don’t see any pink the chicken is ready. Use a fork to remove the chicken to a plate and tent with foil.
9 Finish the sauce: Turn the heat up to medium high. Add 1 tablespoon butter to the sauce. Stir it in and let the sauce reduce uncovered for about 2 minutes. Add the spinach stir to coat a couple of times until the spinach has wilted.
10 To serve: Nestle the chicken back into the pan, and season to taste with salt and pepper.
Bring the skillet to the table. Spoon up chicken, vegetables and sauces into shallow bowls or plates. Serve with crusty bread to sop up the sauce.