Preheat the oven to 180°C.
Spread olive oil and crushed garlic over a baking sheet.
Coat bread slices in the garlic oil and bake for 20-25 minutes until crisp.
Lower the oven temperature to 150°C.
Brown the meat in a hot casserole with oil until mahogany colored on all sides.
Remove meat and fry onions until dark at the edges, about 5 minutes.
Add crushed garlic for 30 seconds before returning meat and stirring in flour.
Gradually stir in the beer and bring to a simmer.
Season with salt, pepper, thyme, and bay leaves.
Cover and cook in the oven for 2.5 hours.
Preheat the grill.
Spread croutons with mustard, sprinkle with cheese, and place on meat.
Grill until the cheese is bubbling and serve immediately.