Preheat the oven to 475 degrees . Line a baking sheet with parchment paper. Add the acorn squash, season with salt and pepper and bake until golden, 25 to 30 minutes.
Meanwhile, in a large saucepan, cook the ground beef, breaking it up, over medium-high heat until no longer pink, about 3 minutes; using a slotted spoon, transfer to a bowl. Add the onion, chiles and corn to the pan and cook over medium heat until the corn begins to brown, about 8 minutes. Stir in the tomatoes, lima beans, black-eyed peas, oregano and beef. Lower the heat, cover and simmer until the black-eyed peas are tender, about 20 minutes. Stir in the baked squash and season with salt and pepper.