In a sachet: 3 T Black Peppercorn, 1 bunch thyme (bruised), 40 bay leaves == use half of sachet for half recipe. Start bacon in cold pot in oil. Render bacon over low heat until crisp. Add leeks, salt and pepper, sweat until soft. Add potatoes, chicken stock, white wine, heavy cream and sachet. Bring to simmer. Cook until potatoes are cooked. Remove sachet. Puree with immersion blender until smooth. Use the water to adjust consistency. Finish by pureeing the butter into the soup. Adjust salt and pepper if needed.