Melt butter and oil in a 10-inch cast iron frying pan over medium heat. Once butter is sizzling, add onion. Sauté until soft and translucent, about 7 minutes. Remove onions from the pan with a slotted spoon and set aside.

Add mushrooms to the same pan. Sauté for 5 to 7 minutes, until mushrooms have softened and released their juices. Turn heat to medium high and continue to sauté, stirring occasionally, until mushrooms are browned and crispy. Add white wine and garlic, reducing heat to medium.

When most of the wine has cooked off, add kale and sauté until kale is cooked but still bright, about 3 to 4 minutes.

Add cream. Simmer, stirring occasionally, until thickened, about 5 minutes. Remove from heat and add cheese, stirring until cheese is completely melted.

Once cheese has melted, spoon the mixture into 8 1/2-cup ramekins. (There might be some mixture leftover — refrigerate and save for another day. Eat within a few days.)

In a small bowl, combine breadcrumbs and melted butter. Spoon breadcrumbs over each ramekin. Broil for 3 to 4 minutes, until golden brown.

Remove from oven. Serve immediately, accompanied by garlic bread.