First make the mashed cauliflower. Remove leaves, cut away any brown spots, trim stem to be flush with the bottom of the cauliflower head, cut into medium size pieces and place in a microwave-safe bowl. Add two tablespoons of water, cover and cook in microwave on high for 5-7 minutes, until tender. Move to a food processor, add 2 tbsp butter and process until smooth. Use 1 1/2 cups of the mashed cauliflower for this dip and place the rest in the fridge for another use.
Next, brown the sausage. Drain and set aside.
Use the same pan (without washing it) to wilt the spinach. Put the spinach in the pan and cook over medium heat until wilted. Move the spinach to a strainer, over the sink or a bowl, and press on it with a paper towel to squeeze out the excess moisture. Set aside.
Using the same pan (without washing it) saute the chopped red peppers with 1/2 tbsp butter for 5 minutes, until softened. Peppers will continue to soften in the slow cooker. Set aside.