Chop and steam 2 heads of cauliflower.
When the cauliflower is fork tender put it into a food processor and puree. If you end up with a chunk that won't puree scoop it out.
Add the shortening, salt, pepper, and 1/4 cup of water and puree. Taste and adjust the seasoning to your liking.
When the beef is cooked add the carrots, celery, bay leaf, Worcestershire, and garlic. Stir for a minute or two until the garlic becomes fragrant.
(If you're making this recipe Whole 30 simply skip to the next step and omit the wine.) Add the red wine to deglaze the pan, scrape up any brown bits from the bottom, and allow the wine to almost completely evaporate.
Dissolve the arrowroot powder in COLD water. If you want your sauce thicker add less water and add more water if you want it thinner. My advice is to start thicker (1.5 cups) because it's easier to add water to thin it out than it is to wait for water to evaporate. Turn the meat sauce to low while you puree the cauliflower.