Step 1 Slice chicken breast fillets horizontally through the centre to make 4 thin fillets. Combine oregano, lemon zest, lemon juice and olive oil in a shallow ceramic dish; add chicken fillets and turn to coat. Cover dish and place in fridge to marinate for 30 minutes.
Step 2 Place a large chargrill pan or a large non-stick frying pan over medium–high heat. Drain chicken fillets of excess marinade, add to pan and cook for 2–3 minutes per side, or until cooked through.
Step 3 Meanwhile, heat extra olive oil in a large non-stick saucepan set over medium heat. Add sliced onion and capsicums to pan; cook, stirring, for 5 minutes, or until soft. Add garlic and cook, stirring, for 1 more minute. Add chickpeas and stock; simmer for 2 minutes. Add chopped kale and cook, tossing with tongs, for 1–2 minutes, or until just wilted.
Step 4 Season chickpeas and kale with cracked black pepper and divide among 4 plates. Top each dish with a chicken fillet and serve with a lemon wedge.