In a large shallow pot or Dutch oven, heat oil over medium-high heat. Add chicken thighs, bone side up. Brown the chicken, turning once, for about five minutes per side. Remove to plate.

Add onions; cook, stirring, for about five minutes or just until beginning to soften. Add curry powder and three tablespoons of water, stirring with a wooden spoon to scrape up any browned bits from the bottom of the pan. Cook for about eight minutes or until the onions are very soft. Stir in jalapeno peppers for two minutes.

Return the chicken to the pan, turning until well coated with onions and spices. Pour in coconut milk. Bring to a boil. Reduce heat; simmer, covered, for 25 minutes. Stir in cauliflower and peas. Cook, covered, for 15 more minutes or until the chicken is cooked through and vegetables are almost tender.

Remove cover; bring mixture to a boil. Boil gently for three minutes or until sauce is thickened. Stir in coriander if using.