Heat 1 tablespoon of olive oil in a cast-iron skillet over medium heat.
Slice the cooked sausage into ½-inch coins and place them into the skillet. Cook for 5 minutes on one side, flip, and cook for an additional 3 minutes.
Transfer the sausage to a large plate and leave any rendered oil in the skillet.
Add the diced bell pepper to the skillet and cook for about 4 minutes, stirring occasionally. If needed, drizzle in a bit more of the reserved sausage oil to prevent sticking.
Remove the bell pepper from the skillet and place it on the plate with the sausage.
Add the sliced zucchini to the skillet and cook for 3 minutes, stirring frequently. Again, add more oil if needed.
Using a sharp knife, slice the kernels off the cooked ears of corn.
Return the cooked sausage, bell pepper, zucchini, and corn to the skillet. Toss to combine evenly.
Stir in the chili powder and heat on low until warmed through, about 2 minutes.
Remove from heat, sprinkle with fresh cilantro, and serve immediately.