Heat olive oil in a large stew pot. Add chopped onions and garlic and saute for 2-3 minutes. Add chopped tomatoes, lima beans, blackeye peas and cajun seasoning. Bring to a boil, stir well, then reduce heat and simmer on low for 30 minutes, stirring occasionally. If the stew gets too thick add water as needed. Add chopped okra, stir well. Simmer for another 15 minutes. Serve over brown rice.