Heat the oil in a large non-stick frying pan over high heat.
Season the chicken and add to the pan. Reduce heat to medium-high. Cook the chicken for 5 minutes each side to until just cooked through. Transfer to a plate. Cover with foil to keep warm.
Place the garlic in the pan. Cook, stirring, for 1 minute or until aromatic. Add the onion and capsicum and cook for 1 minute or until softened. Add tomatoes and stir to coat. Add the wine and cook for 1 minute or until reduced. Add the cream and stock.
Return the chicken to the pan and simmer for 5 minutes or until liquid is reduced. Stir through the spinach until wilted. Season and sprinkle with the basil leaves.