For Calabacitas con Crema: In a large skillet over medium heat the olive oil and butter. Add the onion, garlic, oregano and cumin cook, stirring once or twice, until light and translucent, about five minutes. Stir in the squash, salt, and continue to cook, stirring often, for three additional minutes. Stir in the poblano chiles, corn and cook another three minutes, or until the squash is slightly tender. Stir in the crema and chicken broth, reduce heat and continue to cook, stirring once or twice, until the sauce has thickened, about 3 minutes. Adjust the seasoning and serve immediately on mini sopes.