This workout will be short, but difficult. 1 mile warmup. 800m at mile goal pace, walk 200m. 4x400m at mile goal pace with a 200m walk between each 400m. Half mile cool down.
Here are some splits that you can interpolate between to determine you paces.
Goal Mile 800m split 400m split
4:40 2:20 1:10
5:00 2:30 1:15
5:32 2:46 1:23
6:00 3:00 1:30
6:32 3:16 1:38
7:00 3:30 1:45
7:32 3:46 1:53
8:00 4:00 2:00
8:45 4:22 2:11