Saute the sausage and ham in a large dutch oven over medium heat for about 5 -10 minutes; stirring occasionally. Transfer to a bowl and reserve until later. (Refrigerate if done in advance.) In the same pot, over medium heat, warm the 1/2 cup oil for 2 minutes. Whisk in the flour until incorporated. Cook the roux, stirring constantly, until it is a rich chocolate colored brown, about 15-20 minutes. Add the onion and bell peppers and cook, stirring occasionally until soft, about 8 minutes. Add the garlic and cook 1 minute more. Add tomatoes with their juices, clam and chicken stock, bay leaves, creole seasoning, oregano, and thyme. Increase to medium-high and bring to a boil. Add ocra, reduce heat to medium-low and simmer for 30 minutes to blend flavors. Stir in the sausage, ham, shrimp and crabmeat and cook until the shrimp are pink, 3-5 minutes more. Adjust the seasonings with salt and pepper. Remove from heat and discard bay leaves. Garnish with parsley. To serve, ladle gumbo on top of white rice in soup bowls. Optional: Gumbo is traditionally thickened in two ways, the first being the ocra added during cooking. The second is by adding file powder to the soup just before serving (for this recipe: 1 Tablespoon). Depending on which part of the country you live in, this may be difficult to find in local supermarkets. This gumbo recipe is delicious without the added file powder, if you choose not to use it. If you like it a little thicker, you could also try adding cornstarch to the broth, in lieu of file powder. (I would mix 1 tablespoon cornstarch with 3 tablespoons cold water and add it the soup at the same time as the sausage and seafood.)