This stitch looks like series of crosses or Xs with a knot in between each X. Once you learn this stitch, you can experiment widely with this stitch by making various geometrical patterns like circles. You will then see how the same stitch could look differently wtih each pattern. 🙂

I will follow a slightly  curved line. This stitch is done from left to right.  The thinner the thread or bigger the base, the more it accentuates the feature of this stitch.

sorbello_stitch_1      sorbello_stitch_2
Fig 1: Start by bringing out the needle through A and putting it in through B. Both these points lie above the stitch line. Then, bring the needle out through C which lies right under A and below the stitch line.   Fig 2: Keep the stitch A-B a bit loose. Take the needle under A-B without plucking the fabric beneath.
sorbello_stitch_3 sorbello_stitch_4
Fig 3: Now, once again take the needle under A-B as shown in the illustration.   Fig 4: Pull the needle out to get a knot as shown above and slightly pull it down to bend the stitch A-B towards the centre. Then, put the needle in through D, a point right under B and below the stitch line. Bring it back up again from B as shown.
sorbello_stitch_5   sorbello_stitch_6
Fig 5: Continue the procedure by taking the needle in through E, which lies above the stitch line and bring it out through D. Make the knot and pull the stitch B-E towards the centre so that the knot falls on the stitch line. Keep up with this procedure for the entire design.
  Fig 6: A finished line of sorbello stitch would look like this. Using a thinner thread would have accentuated the features of this stitch.
sorbello_stitch_7   Fig 7: This is a sample of the sorbello stitch done on a broader base. Here, you can see the features of this stitch more clearly.