1. Heat oil in 8-quart stockpot on high heat. Add mushrooms, leeks and garlic; cook and stir until vegetables begin to brown. Deglaze with wine, scraping browned bits from bottom of pan.
2. Add stock, peppercorns, sage, sea salt and thyme; bring to boil. Reduce heat to low; simmer 1 hour.
3. Strain broth through fine mesh strainer. Discard solids. Stir lemon juice into broth. Season as desired with salt and pepper. Pour broth into beverage glasses or mugs. Drizzle each with 1 teaspoon of the avocado oil just before serving.
Make Ahead: Cool broth to room temperature. Cover and refrigerate up to 3 days. To reheat, pour into microwavable mug. Microwave on HIGH 1 minute or until heated through.