What Is This In My Salad?

While dinning out in Vienna I ordered a tomato and cheese salad and it came with the strangest side pickles (?) I'd ever seen.  I couldn't for the life of me figure out exactly what they are.  The flavour was very sour, both in the fruity sense and in the pickled sense.

The texture was the strangest part of all.  The outside is kind of like a hot pepper while the middle is filled with crunchy seeds.  It was almost like eating a hot pepper with no heat at all.  The only thing I could think that it might be would be pickled goose berries, but I'm not sure.

CC