Rare beef steak with herb garlic butter

Name: Rare beef steak with herb garlic butter
Prep time: 15 min
Cook time: 2 h 15 min
Total time: 2 h 30 min
Cuisine: European, British
Ingredients: 2 sprigs fresh flat-leaf parsley, leaves only; 4 sprigs fresh thyme, leaves only; ½ tsp dried oregano; 1 garlic clove; 50 g salted butter, softened; 2 beef fillet steaks (180-200 g each, 3 cm thickness); salt, to season; ground black pepper, to season; 2 dried bay leaves; 1850 g water, plus extra to submerge bags; 30 g freshly squeezed lemon juice or 1 tsp ascorbic acid (see Tips)