Preheat the oven to 180C/350F/Gas Mark 4
Coat the inside of a large casserole dish with the oil and add the chicken breast, peppers, tomatoes and onions.
Add the garlic and season before mixing well with your hands.
Sprinkle the feta cheese on top.
Cover with a lid or foil and place in the middle of the oven for 45 minutes.
Add the spaghetti to a pan of boiling water.
While the spaghetti is cooking heat the tin of chopped tomatoes in a large saucepan. Once it has warmed through, remove the casserole dish from the oven and tip the contents into the pan.
Add a splash of the pasta cooking water to the sauce and stir. Add a bit more if you like the sauce a bit thinner.
Add the pasta to the pan and mix well.
Serve with freshly chopped herbs.
Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.