To start preparing your beef in red wine with chocolate, start with the sauce. Put the butter, rosemary, broth and cocoa in a pan.
Cook everything over medium heat until they start to blend together and the sauce forms.
Pour in the wine, stir, and let the sauce simmer. Season your beef fillets with salt and pepper. Sear the beef in a pan with the olive oil. Be careful, as you want the beef to be juicy not dry.
Once the fillets are done, carefully remove them from the pan, draining as much oil as possible.
Generously coat the fillets with your prepared red wine, chocolate sauce and serve!