Like the idea of more basil, PPL, my seeds are just sitting there doing nothing...
Might be worth trying taking cuttings of your basil, rather than always using seeds.
I have always grown basil from seeds and place the pots by my tomatoes in the greenhouse and they do well.
Important thing is to cut the tops, so they stay bushy from late spring to late Autumn.
But over winter, that does not work.
So last year I went with taking cuttings, cut below a node and have two nodes down the stem and a top of say four or five leaves in good condition and place in a cup of water with both nodes in the water.
After 20 days roots form which is the time to pot the plants on.
This worked great from Late Autumn, through Winter and still supplying nicely now, so have had a constant supply of basil. Taking some regular cuttings from the top, so keeping the plant bushy and encouraging the lower growth. Of course not allowing them to get leggy and not always harvesting all of the tops to eat.
Had them on the kitchen windowsill and its generally about 17-20c there for me.
Will be trying more cuttings in the greenhouse this year along with the seed and see if that works as well or even better than seed.