Beef rump with homemade Sauce Bearnaise and white potatoes

We are big fans of using leftovers, so in this case, we have used meat leftovers from this recipe.  

Beef Rump

The meat goes into the sous vide/water bath at 54 degrees Celsius (129 degrees Fahrenheit) and only needs a little half-hour to heat up all the way to the core. The meat is cooked, so it only requires heating and then searing it in a hot pan to create the browning/Maillard reaction.  

White Potatoes

Peel the potatoes and boil them in salted water for about 20 minutes. If you poke the potatoes with a sharp knife, they should fall off when you lift the knife.  

Sauce Bearnaise

The most important thing when making a Sauce Bearnaise is to have as few temperature differences as possible. So make sure to take your egg yolks out of the refrigerator in advance and ensure that you have melted the butter well in advance so that the temperature can drop significantly. Start by melting the butter in a small saucepan over low heat and pour it into a small jug. You need clarified butter for the dish, meaning the white sediment should be discarded. If you get some of the white part, it’s not a big deal.  Separate your eggs so the yolks are on their own and the whites are on their own. You can use the whites for meringue or to add a little extra to an omelet.  When the sauce is to be combined, there are several different options in our world - directly in a small, thick-bottomed saucepan on the stove, in a bowl over a water bath, or in a kitchen appliance with a heating element (e.g., the Monsieur Cuisine édition plus). In this recipe, we have chosen to do it in a small, thick-bottomed saucepan on the stove over very low heat. Generally, there is a rule of thumb when making these egg-based sauces: Whisk, whisk, and whisk. Keep going and whisk hard - all the time. It’s tough, but it’s worth it 🙂  The essence and egg yolks are whisked together until it foams and thickens.  Then add the butter a little at a time - again, whisking vigorously. Continue for a few more minutes until the sauce is ready. Finally, add the chopped tarragon (we always use a mix of fresh and dried), white pepper, salt, and cayenne pepper. Optionally, adjust the flavor with extra tarragon and lemon juice. The sauce is ready to serve and should be eaten immediately.  Preferably serve it in a small saucepan that has been in the water bath and thus helps keep the sauce at the right temperature a bit longer. You easily risk getting a sauce that becomes too hot if it remains in the pan that was on the stove.