For a vegetarian friendly curry, swap the chicken for cauliflower florets and add ½ cup of red lentils instead. Omit the yoghurt.
No need to brown the cauliflower as you did the chicken. Add the cauliflower and the lentils just after the ground spices and then proceed as normal. Cook until the lentils are cooked through. Adjust liquid accordingly. Taste & adjust seasoning, if required