Place red bell peppers on a baking sheet and sprinkle with olive oil. Place the baking sheet in the oven for 15 to 20 minutes to roast. Once cooked cover the red peppers with aluminum foil and leave for 10 minutes to cool down. Remove the skin and the seeds from the peppers.
In a medium saucepan, crush chicken stock cubes in 4 cups of water and heat it until the cubes dissolve.
Meanwhile, in a pan over medium heat, melt the butter then add the Orzo pasta and stir until lightly browned, remove from heat.
In a large pan on medium heat, melt 2 tbsps of butter then add the onions, cook for 2 minutes then add the tomatoes, red peppers, and thyme, and stir for 5 minutes. Add the chicken stock and turn the heat to low. Blend the soup using the hand blender. Then add the Orzo pasta and cover the soup and leave to cook for 20 minutes. Check seasoning and serve.