Cauliflower Bean Casserole

Directions

1. 1
   Preheat oven to 300 degrees F (150 degrees C).
2. 2
   Bring a large pot of lightly salted water to a boil; cook cauliflower until tender yet firm to the bite, about 10 minutes. Add green beans; cook until tender, about 5 minutes. Drain.
3. 3
   Place bacon in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 10 minutes. Drain bacon slices on paper towels, reserving bacon grease in the skillet.
4. 4
   Cook and stir onion in the skillet with bacon grease over medium heat until tender and lightly browned, about 10 minutes.
5. 5
   Mix cauliflower, green beans, bacon, and onion together in a casserole dish.
6. 6
   Stir butter and mayonnaise together in a bowl; pour over cauliflower mixture. Stir to coat; top with mozzarella cheese.
7. 7
   Bake in the preheated oven until cheese is melted and bubbling, 20 minutes.