Beef and beer slow-cooked pies

Name: Beef and beer slow-cooked pies
Prep time: 15 min
Cook time: 2 h 50 min
Total time: 3 h 5 min
Cuisine: European, British
Ingredients: 50g plain flour; 600g Gravy Beef, cut into 3cm pieces; 36.40 gm olive oil; 2 brown onions, thickly sliced; 4 pancetta slices, coarsely chopped; 200g cup mushrooms, thickly sliced; 4 garlic cloves, crushed; 440ml dark draught beer (optional); 375ml beef stock; 44.40 gm tomato paste; 20.00 ml fresh thyme leaves; 2 sprigs fresh rosemary; 2 dried bay leaves; 6 Red Royale potatoes, very thinly sliced; 50g butter, melted; 2 garlic cloves, crushed; 2.40 gm sea salt flakes; 20.00 ml small thyme sprigs