Option 1 - Cut the stalks and leaves off of the cauliflower and break it into small pieces. Add the cauliflower to an Instant Pot with one cup of water and set it to manual on steam for 10 minutes. Option 2 - Cut the stalks and leaves off of the cauliflower and break it into small pieces. Add the cauliflower to a large sauté pan as well as the 2 T. butter, ½ t. salt, and water. Place on medium/high heat and cover with a lid. Let the cauliflower stead inside the pan for about 5 minutes, until mostly tender. Check the water levels every few minutes to make sure that it doesn’t all evaporate. When almost tender, remove the lid and let the cauliflower sauté for a minute or two, or until lightly caramelized in spots. Turn heat off, cover, and keep warm until ready to toss with the cheese sauce. Heat the 2 T. butter in a saucepan over medium/high heat. Add the squash, carrot, onion, garlic powder, mustard, and salt to the melted butter. Sauté for 5 minutes, or until onion is translucent. Add the can of coconut milk to the saucepan and bring to a simmer. Allow to simmer for about 10 minutes, or until the vegetables are tender and the coconut milk has reduced by 2/3 and is thick. Pour the vegetables and coconut milk into a blender and puree until very, very smooth. Immediately add an egg yolk to the puree and blend well. The hot puree will cook the egg which will thicken the sauce and give it a rich texture. Check seasonings and add more salt or pepper to taste. Pour over the hot cauliflower and toss to coat. Serve.