Heat the olive oil in a large pot over medium heat. Add the diced onion and cook for 4 minutes until it softens.
Stir in the minced garlic, minced chipotle peppers, and cumin. Cook for 1 minute until fragrant.
Add the diced tomatoes and cook for 3 minutes, stirring now and then, until they begin to release their juices.
Pour in the vegetable broth and bring the mixture to a gentle simmer. Add the corn kernels and cook for 5 minutes.
Season the sea bass pieces with a pinch of salt and pepper, then add them to the pot. Simmer for 6 to 8 minutes until the fish turns opaque and flakes easily.
Remove the pot from the heat and stir in most of the chopped cilantro. Taste and adjust salt or pepper if needed.
Ladle the stew into bowls and serve with lime wedges on the side.