Preheat the oven to 200C/180C Fan/Gas 6.
Place the chicken thighs and red onion into a large roasting tin. Drizzle with 2 tbsp of olive oil, season with some salt and pepper and toss to coat.
Roast in the oven for 25 minutes then add the tomatoes and garlic and roast for a further 5 minutes until the tomatoes are just soft and the chicken cooked. Remove from the oven and top with the goat’s cheese.
Meanwhile, cook the spaghetti according to the instructions on the pack and add the peas 4 minutes before the end of the cooking time. Drain well and toss through the remaining olive oil and some salt and pepper.
Place the spaghetti and peas into a warm serving dish and top with the chicken, tomatoes and goat’s cheese.
Scatter some chopped parsley and basil leaves over the spaghetti and serve immediately.