In food processor, purée poblano peppers and liquid until smooth; set aside.
Chop green onions, reserving 1 tbsp for garnish.
Meanwhile, in large saucepan, heat butter and oil over medium heat; sauté rice for 3 to 5 minutes or until lightly toasted. Add garlic and remaining green onions; sauté for 3 to 5 minutes or until softened.
Stir in broth, milk, cream and poblano purée; bring to boil. Cover and cook for 40 to 45 minutes or until rice is tender. Season with salt and pepper.
Stir in 1/4 cup cheese until cheese is starting to melt. Stir in cilantro. Remove from heat. Garnish with remaining green onions and cheese.
Serve with lime wedges if desired.