Perfect steak with sauce Bernaise

• 2 beef fillet steaks (3-6 cm thickness)
  ή beef rump steak (3-6 cm thickness)
• sea salt, to season
• ground black pepper, to season
• olive oil, to drizzle

Bernaise sauce

• 4 - 5 sprigs fresh tarragon, leaves only; stalks reserved
• 80 g eschalots
• 80 g white wine vinegar
• 180 g unsalted butter, cut into pieces
• 4 egg yolks
• ½ - 1 tsp salt
• 2 pinches ground black pepper