Dice meat into small cubes. In a pan melt the butter and fry the meat until lightly browned. Remove meat and add the onions, gently cook for 2 minutes. Deseed and slice the red pepper, then blanch in a little boiling water. Place the vegetables and meat in a casserole with the peaches and a tablespoon of syrup from the can.
Dissolve the stock cubes in boiling water and add lemon juice, bring to the boil. Moisten flour with a little cold water, work into the boiling stock and allow to thicken slightly. Then pour the sauce over the meat and vegetables in the casserole. Cover and cook in a moderately hot oven (375°F, 190°C, gasmark 5) for 1 hour.