Heat olive oil and coconut oil in a skillet over low heat; cook and stir onions in the hot oil until tender and golden brown, about 1 hour. Remove caramelized onions from pan.

Increase heat under skillet to medium-high heat. Sprinkle Chinese five-spice powder over turkey. Cook and stir turkey in the hot skillet until browned and crumbly, about 10 minutes.

Mix coconut milk, water, rice, caramelized onions, and pineapple into the ground turkey. Bring to a boil, reduce heat to low, and simmer until rice is tender, about 25 minutes.

Preheat oven to 400 degrees F (200 degrees C). Grease a 9x13-inch casserole dish.

Bring a pot of water to a boil; cook red bell pepper halves in the boiling water until slightly softened, about 10 minutes. Drain.

Arrange red bell pepper halves in the prepared casserole dish; spoon turkey mixture into each half. Top each stuffed pepper with a slice of pepper jack cheese.

Bake in the preheated oven until cheese is melted and bubbling, about 20 minutes.