- Heat a large saucepan or Dutch oven over medium-high heat. Add ground sausage, breaking up the meat. Cook, stirring occasionally until browned and cooked through about 5 minutes.
- Using a slotted spoon, remove cooked sausage and allow to drain on a plate covered with paper towels. Discard drippings, but do not wash pan.
- Chop the onion and carrot into pieces. Crush the garlic clove. Melt butter over medium heat. When bubbling subsides, add onion and carrot. Cook until onion begins to brown on the edges and becomes somewhat translucent.
- Stir garlic into onion and carrot mixture. Cook one minute. Add red wine vinegar and cook until syrupy, scraping up browned bits about 1 minute.
- Stir in oregano, basil, sage and red pepper flakes. Pour in stock and heavy cream. Increase heat to medium-high.
- When soup reaches a simmer, add cauliflower and turn heat down to medium-low. Simmer uncovered until cauliflower is fork-tender, about 10 minutes. Stir in kale and cooked sausage. Cook 1 to 2 minutes longer, or until kale wilts and the sausage is reheated.
- Season to taste with salt and pepper. The amount of salt needed may vary due to variation in brands of broth.