They both need cooked quite differently, so you can’t just throw it all in a pan and hope for the best!
Make sure you take your steak out of the fridge about 20 minutes before cooking, to let it come up to room temperature slowly and avoid the fibres from tensing up when you start cooking.
When it’s ready, pat it dry with a paper towel and lightly oil one side. Put it in a heavy-based, pre-heated pan and leave it – no need to prod or poke at it until it’s time to turn. There are lots of ways to know when it’s cooked the way you want it, but the easiest by far is to use a meat thermometer. Takes out any guess work.
Once it’s cooked to your liking – medium-rare for me, get it resting – take it out of the pan and leave it to rest before serving.
Whilst it’s resting, sauté your seafood. I like to use a fresh pan to keep all the flavours separate. It doesn’t take long. Sear hot in a little oil then add a bit of butter at the end when they are almost cooked let it melt and foam lightly but don’t overcook the seafood. Simply spoon the cooked seafood and butter over your steak before eating.