• Peel and coarsely chop enough onion to measure 1 cup [2 cups].
• Cut the mushrooms in half lengthwise; cut any large mushrooms into quarters.
• Zest and juice the lemon, keeping the zest and juice separate.

• Pat the chicken dry with a paper towel; season generously with salt and pepper.

In a large frying pan over medium-high heat, warm 1 to 2 tablespoons oil until hot but not smoking. Working in batches if needed, add the chicken and cook, without turning, until browned on one side but not yet cooked through, 3 to 4 minutes. Transfer to a plate. Add more oil between batches if needed.

Add the onion and mushrooms to the pan, season with salt and pepper, and cook over medium-high heat, scraping up any browned bits from the bottom of the pan, until the vegetables are lightly browned and starting to soften, 3 to 4 minutes. 

Return the chicken, browned side up, and any accumulated juices to the pan. Add the artichokes and 1 cup [1½ cups] water. Bring to a boil and cook, scraping up any remaining browned bits from the bottom of the pan, until the liquid has thickened slightly, 2 to 3 minutes. Add the herb blend and spinach, in batches if needed, and season with salt and pepper. Reduce to a simmer and cook until the sauce has thickened, the spinach is wilted, and the chicken is cooked through, 3 to 4 minutes. Remove from the heat and stir in 2 tablespoons [¼ cup] lemon juice. Season to taste with salt and pepper.
While the chicken and vegetables simmer, prepare the almond-olive relish.

• Coarsely chop the almonds.
• Coarsely chop the olives.

In a small bowl, stir together the almonds, olives, lemon zest, and 1 tablespoon [2 TBL] oil. Season to taste with salt and pepper.

Transfer the chicken, vegetables, and sauce to individual bowls. Top with the almond-olive relish and serve.