Complex sentence: Many Vietnamese immigrants in the Southern U.S., particularly in Louisiana, use the regional dark French roast, often with chicory; otherwise they use an imported Vietnamese-grown and medium roasted coffee without chicory.
Split into simpler sentences: Many Vietnamese immigrants in the Southern United States, particularly in Louisiana, use the regional dark French roast coffee, often with chicory. Otherwise they use an imported Vietnamese-grown and medium-roasted coffee without chicory.