1) In a small saucepan, add barbecue sauce and heat at low.
2) Add beef slices and let them cook for some time.
3) Take a sauté pan and cook spinach until crisp tender.
4) Season it with salt and pepper.
5) To make dessert, in a blender jar add beer and churn until smooth.
5) Take the bread and place beef slice, cheese, spinach and the other bread piece.
6) Serve the roast beef sandwich and ice cream shake immediately.