I had quite some coffee butter lying in our fridge waiting for me to try out one of the plated egg dishes in Modernist Cuisine, one I never got round to making. Then I remembered I saw this egg dish on some blog (I completely forgot where, so leave me a message if you know), consisting of a soft-boiled egg with white radishes on unidentified green vegetables. The presentation looked nice, and it got me thinking about a breakfast/tapas dish that doesn’t take too long to prepare. I used regular radishes for this one, prepared sous-vide, and chopped/sliced spring onion for the green vegetables. The coffee butter is used to quickly fry the radishes and onions a bit. I used the guidelines in Modernist Cuisine for the soft-boiled egg.
The result was a well-balanced dish: the egg was silky smooth with a slightly runny yolk (honestly, sous-vide eggs are divine), the radishes and onion perfectly accompanied the egg while giving a very subtle hint of coffee. This one is a keeper!
Quick and dirty recipe
The eggs are first cooked in boiling water for two and a half minutes, then cooled completely. Afterwards, they are cooked in a water bath at 65°C for 40 minutes. Then cooled again, heated with a blowtorch, and peeled. They can be kept like this for two days; to reheat simply warm them in a batch at 60°C for half an hour. From Modernist Cuisine.
The coffee butter is made by sealing 175gr coffee beans and 125gr unsalted butter in a mason jar. Then the jar is steamed for 3 hours. Et voilà, coffee butter. From Modernist Cuisine. (Note: the coffee butter had a really pungent smell when I used it, not at all enjoyable, but the end result was worth it. Don’t know if it is supposed to behave like this, it could also be due to some coffee beans being fried for a while with the butter in the hot skillet.)
The radishes are cooked sous-vide at 85°C for 45 minutes. Again, from Modernist Cuisine.
I sliced the bottom part of the onions in 1mm oblique cuts and made a rough julienne from the upper part. You can of course cut it whichever way you like! Then quickly sauté the chopped spring onions and radishes in the coffee butter (just enough to heat them through). Serve with the heated egg, add salt and pepper to taste. (Instruct the guests to make a cut halfway the egg lengthwise and about three-quarters of the egg wide.)