Ingredients

For the peppers and assembly:

• 8 medium poblano peppers
• 4 ounces Monterey Jack cheese, shredded or thinly sliced
• Finely chopped fresh parsley leaves, for garnish (optional)

For the tomato sauce:

• 1 tablespoon olive oil
• 1 medium yellow onion, diced (about 1 1/2 cups)
• 6 medium Roma tomatoes, diced (about 3 cups)
• 2 cloves garlic, minced
• 2 sprigs fresh oregano
• 1/2 teaspoon kosher salt, plus more as needed
• 1/4 teaspoon freshly ground black pepper

For the filling:

• 16 ounces frozen corn kernels (about 2 cups), thawed
• 1 tablespoon olive oil
• 1 small yellow onion, finely diced (about 1/2 cup)
• 1 medium Roma tomato, finely diced (about 1/2 cup)
• 1 teaspoon kosher salt
• 1/4 teaspoon freshly ground black pepper
• 1 dried bay leaf

1. Roast the peppers:
2. Arrange a rack in the upper third of the oven (or about 7 inches from the broiler) and heat the oven to broil. Line a rimmed baking sheet with aluminum foil.
3. Place 8 medium poblano peppers on the baking sheet and broil until mostly charred and blistered on all sides, flipping halfway through, 10 to 12 minutes total. Transfer to a large heatproof bowl and cover tightly with plastic wrap. Let sit for at least 10 minutes for the peppers to steam. Meanwhile, heat the oven to 375ºF. Make the sauce and filling.
4. Make the tomato sauce:
5. Heat 1 tablespoon olive oil in a medium skillet over medium heat until shimmering. Add 1 diced medium yellow onion, 6 diced medium Roma tomatoes, 2 minced garlic cloves, 2 fresh oregano sprigs, 1/2 teaspoon kosher salt, and 1/4 teaspoon black pepper. Cook, stirring occasionally, until the onion is softened and the tomatoes have released their juices, about 5 minutes.
6. Turn off the heat. Remove the oregano stems and set aside. Transfer the sauce to a blender or use an immersion blender and blend until smooth.
7. Return the sauce to the skillet and add the reserved oregano stems. Bring to a boil over medium heat. Continue to boil, stirring occasionally, until sputtering, about 5 minutes on low heat. Pour the sauce into a 9x13-inch baking dish. Wipe out the skillet and use for the filling.
8. Make the filling:
9. Heat 1 tablespoon olive oil in the now-empty skillet over medium heat until shimmering. Add 16 ounces thawed frozen corn kernels, 1 finely diced small yellow onion, 1 finely diced medium Roma tomato, 1 teaspoon kosher salt, 1/4 teaspoon black pepper, and 1 dried bay leaf. Cook, stirring occasionally, until the tomatoes and onions soften, about 5 minutes. Take the skillet off the heat.
10. Assemble and bake the chile rellenos:
11. Peel the poblanos (use a paper towel to help rub off the skin if needed, but do not rinse) and return to the baking sheet. Using a paring knife and starting from the stem end and working down to the tip, cut a long slit into each pepper; do not cut all the way through the other side of the pepper.
12. Being careful not to tear the peppers, scrape out the seeds and membranes from each pepper with a spoon and discard. If you’re having trouble scraping the seeds from the peppers without tearing them, try using your hands instead. Don’t worry if you do tear them — the sauce will hold the peppers in place so you can still stuff them.
13. Place the peppers slit-side up in a single layer on the sauce in the baking dish. Divide the filling between the peppers (heaping 1/4 cup each) and spread into an even layer. Top the filling evenly with 4 ounces shredded or thinly sliced Monterey Jack cheese. Cover the baking dish with aluminum foil.
14. Bake until the sauce is bubbling and the cheese is melted, about 15 minutes. Garnish with freshly ground black pepper and finely chopped fresh parsley leaves if desired.