4x 400m @ 1/2 marathon pace (so about 20-30 sec. slower than 5k pace per mile….break it down).  Recovery is jog/walk across the grass to the start.

4 x 400 @ 5k pace (you haven’t run any 5k’s lately so adjust :))  Recovery is same as above.

2-4 x 200m @ fastish pace. 200m recovery.

 

If you want to add more; then take away the 200’s and add:

4 x 400m @ faster than 5k pace.; you still have walk across the grass recovery.