Preheat the oven to 160Fan/180C/Gas 4. Place the onions, carrots, anchovies and their oil, onion confit, garlic and Herbs De Provence in an casserole pot with a lid.
Heat the duck fat in a frying pan and fry the bacon lardons for 5-10 minutes until cooked though. Add them to the casserole pot.
Cut the beef into chunks, I like mine quite small, no more than 2cm cubes. Place the meat in a plastic bag and add the flour and lots of seasoning. Shake the meat around to coat well with the flour.
Heat the olive oil in a frying pan and fry the beef coated in all the flour, in batches if necessary, just to brown it and give it good colour. Then add the beef to the pot with the vegetables.
In the frying pan, add the red wine and scrape all the beefy bits off the bottom of the pan. Just heat for 3 minutes and then pour into the pot. Put the lid on and put it in the oven for 2 hours 20 minutes. Check halfway to make sure that their is enough liquid. If it looks a little dry, just add some water.
Meanwhile, thinly slice the baguette and mix the butter with the Marmite in a ramekin. Spread each slice of baguette with a little of the Marmite mix.
Take out the beef and add the mushrooms and stir. Arrange the toasts on the top slightly overlapping. Place back in the oven with the lid off for the last 40 minutes.
Serve generously with a good dollop of creamy mashed potato.