Make the roux:
Start the gumbo by making a roux, which will add a lot of flavor and thicken the gumbo. Heat the cup of peanut oil or lard (both are traditional roux ingredients) over medium heat for a minute or two and then stir in the flour. Mix so there are no lumps. Cook the roux over medium-low heat until it is the color of chocolate. It is your choice how dark you let your roux go. The darker it is, the better, but once the roux gets dark it can burn easily, so you must stir constantly and keep and eye on it.

Heat water to a simmer:
While the roux is cooking, bring the 10 cups of water to a simmer.

Add onions, celery, green pepper, then garlic to roux:
When the roux is dark enough, mix in the chopped onions, celery and green pepper and turn the heat to medium. Let this cook, stirring occasionally, until the vegetables soften. Add the garlic and cook another 1-2 minutes

Add bay leaves, spice, hot water:
Add the bay leaves, the Cajun spice and slowly stir in the hot water. The roux will seize up at first, but keep stirring and it will all come together in a silky broth.

Add ham hock, greens, cover and simmer:
Add the ham hock and all the greens. Taste for salt, but remember the ham hock will be salty, so let the broth be a little under-salted for now. If you want to add more Cajun spice, do so now. Cover the pot and simmer gently for 1 hour and 15 minutes.

Remove meat from ham hock bones, chop and return to pot:
Check the ham hock. If the meat is falling off the bone, remove it, discard the bones, chop the meat and return it to the pot. If the hock is not ready, keep simmering the gumbo; ham hocks don’t always cook at the same rate.

Add andouille sausage:
Once the hock is ready, add the andouille sausage and cook for another 15 minutes.

Serve with file powder at the table.

Remove the stems from the mustard greens, wash the leaves, and drain them.

Heat the olive oil in a large saute pan and add the garlic. Let it sizzle for an instant and then add the greens. Cook, covered, for about 5 minutes, until the greens are tender.

Let them cool, season with a pinch of red pepper flakes, the vinegar, salt and pepper, and more olive oil, if necessary, to moisten them. Chop the mixture coarsely.

Lay the prosciutto slices out on a flat surface and cut them in half. Place a small ball of the greens on each piece of prosciutto and roll the greens up inside. Or instead of making little rolls, serve the greens on the center of a platter surrounded by the prosciutto.