Preheat the oven to 200°C (400°F).
Heat butter and olive oil in a large frying pan over medium heat.
Add chicken, cayenne pepper, paprika, onion powder, garlic powder, chicken seasoning, and dried parsley. Cook for 4–5 minutes until lightly browned.
Stir in sweet soy sauce, soy sauce, sambal, and cooking cream. Simmer until slightly thickened.
Add the grated cheese and stir until melted and combined. Remove from heat.
In the same pan, cook the chopped onion for 5–7 minutes until caramelized.
Mix the caramelized onions with grated cheese and chopped parsley.
Cut the sandwich rolls in half and gently press down the center to create a cavity.
Place a layer of cheddar cheese inside each roll.
Fill each roll with the spicy chicken mixture.
Top with the onion and cheese mixture.
Arrange the sandwiches in a baking dish and bake for 5–7 minutes, or until the cheese is melted and bubbly.
Serve hot and enjoy.