2 Tbsp olive oil
8 small chicken breast fillets, trimmed
1 brown onion, finely chopped
2 cloves garlic, crushed
3 anchovy fillets, drained, finely chopped
200g button mushrooms, trimmed
1 green capsicum, deseeded, thickly sliced
1 small carrot, peeled, diced
1 tsp dried oregano
1/2 cup chicken stock
2 cups tomato passata
1 cup pitted kalamata olives
2 Tbsp balsamic vinegar
Sea-salt flakes and freshly ground black pepper, to season
1/4 cup roughly chopped flat-leaf parsley
Heat 1 tsp of the oil in a large, deep frying pan over a high heat. Cook 1/2 the chicken for 2 minutes each side or until golden. Transfer to a plate. Repeat with 1 tsp more of the oil and remaining chicken. Remove from pan and set aside.
Reduce heat to medium. Add remaining oil with onion, garlic and anchovies, and cook, stirring occasionally, for 5 minutes or until onion is softened and anchovies are dissolved. Increase heat to high, add mushrooms, capsicum and carrot, and cook for 2-3 minutes or until softened.
Add oregano, stock and passata, and bring to the boil. Return chicken to pan, poking it into sauce. Reduce heat to medium-low and cook, covered, turning occasionally, for 15-20 minutes or until chicken is cooked through and sauce is slightly thickened. Add olives and vinegar, and cook for 1-2 minutes. Season with salt and pepper. Scatter over parsley and serve.