1. Cut the onions, then the bacon.
2. Cut the meat into 5 cm by 2 cm cubes.
3. In an ovenproof casserole dish, brown the meat in butter.
4. Before removing the meat, add the bacon to precook it.
5. Replace the meat with the onions to brown them.
6. Add the brown sugar and reduce the heat so that the onions caramelize slightly.
7. Off the heat, alternate the meat and onions in the casserole dish, season with salt and pepper, and add the bouquet garni.
8. Pour beer into the dish until it reaches the level of the meat.
9. Cover the preparation with stale bread spread with mustard.
10. Cover and place in a low oven for 3 hours at 90°C-120°C (thermostat 3-4).
11. I use a small Gueuze beer, or a mix of brown and blonde beer.