In a large pot heat oil over medium high heat.
Once oil is warm sauté celery, carrots, and onions along with the salt.
After about 5 minutes, add the red bell pepper and sauté for another few minutes.
Once veggies are mostly soft and onions are translucent, add the garlic, cooking for another minute stirring frequent to prevent burning.
Add the spices, cooking for about 30 seconds while stirring frequently to prevent burning.
Add the Rotel (or diced tomatoes and green peppers if you can't find Rotel), cooking for about 30 seconds.
Add the stock and black beans to the pot, stir all together and bring to a boil.
Let soup simmer covered on low for 30 minutes, stirring every 10 minutes or so to prevent beans for sticking to the bottom of the pot
While sou is simmering, thaw the frozen corn by putting it in a bowl of hot water and letting it sit until soup has cooked and been partially pureed.