In a large skillet, heat the avocado oil over medium heat until shimmering. Add the sausages and cook until heated through, and golden brown on all sides, 7 to 9 minutes. Transfer to a serving plate.
Add the butter to the pan and let melt. Add the shallot and cook, stirring frequently, until translucent. Add the mushrooms and sauté until golden brown, about 5 minutes. Sprinkle with salt and pepper and the sage.
Pour the marsala over the mushrooms and let cook until the wine is reduced by about half. Add the broth and the whipping cream and bring to a boil. Let cook until sauce is thickened.
Pour mushrooms and sauce over the sausages. Serve over cauliflower rice or mashed cauliflower.
Food energy: 341kcal Total fat: 28.06g Calories from fat: 247 Cholesterol: 128mg Carbohydrate: 5.55g Total dietary fiber: 0.44g Protein: 16.77g