Preheat oven to 180°C / 160°C fan forced. Spray roti with olive oil cooking spray and press into a 6-hole Texan muffin pan. Bake in the oven for 12-14 minutes or until golden brown.
Meanwhile, heat oil in a large non-stick frying pan over medium heat. Add chicken and cook for 5-6 minutes or until browned on all sides. Transfer to a plate. Drain excess fat and discard.
Add onion and cook for 5 minutes or until softened. Pour Passage to Butter Chicken Simmer Sauce and ¼ cup water into pan and bring to a simmer. Return chicken to pan, coating well with sauce. Cover, reduce heat and simmer for 10 minutes or until chicken is cooked through, adding peas for the last 2 minutes.
Spoon butter chicken into roti bowls. Serve with yoghurt and coriander, if you like.