Chop the cauliflower and add it in. Keep sauteing until cauliflower starts to soften.
Add half and half as well as well as salt and pepper.
Pour everything in a blender (be careful with the heat). Puree well until everything is smooth. Add a bit of water if needed. You need the mixture to be puree consistency not too watery. Transfer back to the pot and add 1 more tbsp of butter. Check that puree is good on salt and pepper and adjust to your taste.
Clean and prepare the peppers. I like cutting them in half for this recipe. Stuff them with the pureed cauliflower.
Add olive oil to the baking dish as well as a half cup of water. Bake at 375 for 45 minutes. You might add few tbsps of water if needed half way through the baking process if the dish is completely dry. Or you can cover with aluminum foil.
Once you are ready to serve, sprinkle with parmesan cheese and green onions.