Melt margarine in a skillet over medium-high heat. Cook and stir onion and bell pepper slices until slightly softened, 3 to 5 minutes. Add cabbage, water, garlic, and thyme; bring to a boil. Reduce heat to medium; cover and cook until cabbage is tender, 8 to 10 minutes.
Place scotch bonnet chile in the skillet and stir. Add salt and pepper. Simmer 2 or 3 minutes more.