1. Preheat oven to 350 F. Lightly oil a 3 qt casserole dish
2. Cut cauliflower into bite-sized florets with plenty of stem. Place in a large pot and add 1 inch of water to the bottom. Bring water to a boil over high heat, cover with a tight fitting lid and steam cauliflower until tender, about 7 minutes.
3. Drain cauliflower in a colander. Reserve half of the florets. Place the other half into a blender, add cream and blend until smooth. Pour cauliflower cream back into the large pot and add salt, pepper and 1 cup of cheese. Cook over medium heat, stirring occasionally, just until the cheese is melted.
4. Stir lentils into the cream sauce and taste for seasoning. Add a little more salt if necessary. Spread 3/4 of the lentil mixture over the bottom of the prepared casserole dish.
5. Add reserved whole florets to the pot, stir gently to coat in remaining cheese cause without breaking apart the cauliflower.
6. Arrange cauliflower on top of the lentil mixture, using a spatula to scrape all of the sauce out of the pan. Sprinkle remaining cheese over the top, followed by the chopped bacon.
7. Place on the middle rack of the oven and bake for 25 minutes or until casserole is bubble around the edges and cheese is melted. Serve hot.