Cream Of Beet Soup

• 1 onion
• 1 marjoram sprig (fresh)
• 550 gr chicken
• 240 ml cream (heavy)
• 190 gr beets
• 32 gr herbs (chopped fresh)
• 26 gr butter (unsalted)
• 30 ml good wine vinegar (red)
• 2 gr of thyme (dried chopped fresh)