In a large skillet or saucepan with a lid, melt the butter over medium heat. Add the chopped veggies and Rotel. Season lightly, stir, then cover, cooking 10 -15 minutes for veggies to wilt. Add okra, stirring, then cover and let cook another 10 -15 minutes. Add chicken stock. When it's warm, add the roux, if you want to thicken it. If you're adding tomato paste, now's the time. Cover and let simmer for another 10 - 15 minutes. Add the shrimp, season well with Magic Swamp Dust cajun seasoning. Stir to incorporate. It's done with the shrimp are pink all the way through. Serve over cooked rice.