Season the chicken: Pat chicken dry. Toss with salt, pepper, paprika, oregano, and red pepper flakes.
This quick rub builds flavor and helps with browning.
Sear the chicken: Heat olive oil in a large skillet over medium-high heat. Add chicken in a single layer and sear 3–4 minutes per side until browned. It doesn’t need to be cooked through yet.
Transfer to a plate.
Soften the aromatics: In the same skillet, reduce heat to medium. Add onion and a pinch of salt. Cook 3–4 minutes until softened, scraping up browned bits.
Stir in garlic and cook 30 seconds until fragrant.
Add the veggies: Add red bell pepper and zucchini. Cook 3–4 minutes, stirring occasionally, until slightly tender but still bright.
Build the sauce: Pour in diced tomatoes with juices and the chicken broth. Stir and bring to a gentle simmer.
Return the chicken: Nestle the browned chicken and any juices back into the skillet.
Simmer 6–8 minutes, stirring once or twice, until the chicken is cooked through and the sauce slightly thickens.
Finish with briny and fresh notes: Stir in Kalamata olives, lemon zest, and lemon juice. Cook 1–2 minutes. Taste and adjust salt, pepper, or lemon as needed.
Top and serve: Remove from heat.
Sprinkle with feta and parsley. Serve as is, or spoon over couscous, rice, or orzo. Add extra feta if you like.