Boeuf bourguignon avec Mousse au champagne sur la purée de patate douce

INGREDIENTS (for 4-6 people):
1.5 kg beef, cut into cubes (slightly streaky, goulash meat)
3 pieces of beef bone 
6 carrots
2 hands full of mushrooms 
½ leek stick 
5 shallots
200 gr smoked bacon, diced 
4 cloves garlic 
1 bay leaf 
1 small bunch of fresh rosemary, thyme and tarragon 
4 tbsp spelt flour 
rapeseed oil 
salt 
pepper

PREPARATION:

1. Heat rapeseed oil in a roaster or large pot. Brown the beef from all sides.
2. Add two tablespoons of spelt flour and mix well.
3. Then add the beef bone and the bunch of herbs (bound with a thread) as well as the bay leaf and gradually deglaze with red wine. The process should take about 1.5-2 hours.
4. Heat some rapeseed oil in a separate pan and sauté chopped shallots, pressed garlic and diced bacon.
5. Add both to the meat in the roaster/pot.
6. Wash leek and cut into rings.
7. Clean and halve the mushrooms. Peel the carrots and cut them into rings.
8. Place the vegetables in the roaster and simmer at low heat for about 1 hour.
9. Remove the bay leaf, bones and herb and divide into plates.
10. Season with salt and pepper.
11. Serve as desired with fresh thyme, champagne cream and mashed sweet potatoes.