Two sessions below.
This is a bit of an experimental session - unfortunately I haven't had a chance to try it myself, but I think it will work.
5 pieces (10', 8', 6', 4', 2'), on 2 minutes rest.
Rates change every 2 minutes: 16 to 24 in the first piece, 18 to 24 in the second, 20 to 24 in the third, 22 to 24 in the fourth, and 24 in the fifth piece.
The physiological rationale is that this is just another arrangement of 30 minutes of work, so still mainly focussing on aerobic base.
The technical / mental rationale is that this one is a tricky exercise in pacing. You want all your splits at a given rate to be even across the pieces. But usually the challenge is to reign back in the first piece so that you can hagn on in the last piece; today it's almost the opposite - you need to make sure that you go hard enough in the first long piece that you are just about holding on in the last piece - you don't want to end up with loads left in the tank! Tricky, and nobody is going to hit it exactly, but worth giving it a go I think to keep working on developing our ability to pace ourselves.
Suggested second session for the week
3 x 2k, r 20, on 2:00 rest.
Like last week, this is being a bit non-orthodox and making two progressions in one session - increasing the distance per piece, and decreasing the rest. Ah well, we'll give it a go! See how close you can get to the total distance covered in the 6 x 1km and 4 x 1500m pieces from previous weeks - you should be started to get a bit of an idea of what split you could aim for in a 5km test.