What can I plant here?

[shoutyshouter]

So our neighbours just before we moved in planted this box hedging between our houses, slap bang in the middle of a metre wide border.
They're more spaced out than this though so look more like individual plants than a hedge.
It's by the by, but they're actually mainly on our side of the border the way they've grown!
That was 2 years ago and they're maybe 30cm tall, not sure how big they grow?
Anyway, we've been left with an 8 inch strip in front of these bushes on our side that end up full of weeds.
I want to plant something to cover the soil so I don't need to weed. Something with good ground cover.
I was thinking lavender, but will that totally smother the box hedging that's already there?
Any other ideas?
Photo below.

Well firstly, OP, if it’s growing on your side of the border, you can cut it right back to the boundary line. That might give you a better width of border to play with.
Next, you could dig down to remove roots, again right up to the boundary line, then put a root proof barrier in along the length of the border. Replace with good quality topsoil and you can then grow whatever you fancy, completely unaffected by the neighbours’ hedge plants.

How high is the box, and how high do you want your stuff to be? Is it very sunny, or shaded?

The box plants are around 30cm high. It's a very sunny spot. I want something that will spread, but I think if it smothered the neighbours box bushes they might be a bit cross!

In fact the photo I've added is a pretty accurate representation of how much soil is left in front of the box bush. I'm just an awful gardener with no time or patience for weeding.
Could I perhaps put a membrane on that strip with some bark maybe?

I'd go for ground cover plants like aubretia as Weary has suggested. Things like creeping phlox and creeping thyme are evergreen too.

rhododendron?

www.bbc.com/news/world-us-canada-39966325

Aubretia would be lovely, as would creeping thyme.