In a skillet over medium heat, add the curry powder and stir a few seconds until it becomes fragrant. Stir in the oil. Cook the chicken in the seasoned oil for about 5 to 8 minutes on each side, or until done.
Spread chutney sauce on one side of each croissant, and the mayonnaise on the other side. Cut the cooked chicken to fit the croissants (I cut them into slices), and layer with lettuce, tomatoes, and red onion. Sprinkle with a little salt and pepper, and serve.