There is nothing earth shaking about sous vide celery hearts, except that they work and I use them in presentations. People ask me what they are. Here it is:
Remove the darkened root portion. This can also be done later, basically a preference in real time.
Cut it down to about 5″/40 mm. Slice lengthwise.
Make diagonal cuts at the tip to make a point.
If you slice them thick enough, and with a little luck, you can make them stand up on edge.
Process sous vide at
183 F/84 C X 1 hour,
shock in ice water. The juices are great for stock or even just to sip.
Pat dry, season, spray a little aerosol release or a few drops of oil and grill, sear, roast, etc.
What it lacks in color it gains in dimension. Crunchy, and tasty if well seasoned. Most people just throw them out.