Position whole poblano peppers on a baking sheet and place under a broiler for 6 to 8 minutes, turning once to ensure even charring. Once blistered, set aside to cool.

Preheat oven to 375°F and lightly grease an 8x8-inch baking dish.

In a large saucepan or Dutch oven, warm the olive oil over medium heat. Add the diced onion and salt, cooking for approximately 5 minutes until the onion becomes soft and translucent.

Incorporate the rice into the saucepan, stirring briefly before pouring in the vegetable broth. Bring the mixture to a boil, then cover and reduce the heat to a low simmer. Cook for 10 to 12 minutes until the rice is tender and the liquid is absorbed.

Meanwhile, peel the cooled poblanos to remove the charred skin, discard the seeds, and dice the flesh.

Combine the cooked rice with the diced poblanos, thawed corn, sour cream, 1 cup of the shredded cheese, and chopped green onions. Stir until everything is evenly distributed.

Spoon the rice mixture into the prepared baking dish and sprinkle the remaining 1/2 cup of cheese over the top.

Bake for 25 to 30 minutes, or until the dish is bubbling and the cheese is fully melted.

Garnish with preferred toppings and serve while warm.