Heat butter and oil in a large saucepan. Saute onion until translucent, and then add the garlic and spices. Add rice and cover with broth. Cover and simmer for 20 minutes.
Remove rice mixture from the pan, place in a large bowl with crawfish and goat cheese. Add cilantro and lemon zest and incorporate all ingredients gently with a wooden spoon.
Fill the poblanos with the filling, trying not to break chile apart. Serve with Goat Cheese Sauce.
Heat on low whisking constantly until comes together and coats the back of a spoon. Season with salt and pepper.