One plant to try is definitely garlic imo- I have a patch of it in my yard and if I don't look at it for a month, it's fine. The scrapes off the top of the plant make great salads and stir-fry, and they seem to dissuade certain bugs from wanting to hang about.
I adore how many different herbs you have, I think it is more motivational to cook something special when you have fresh herbs about. Or make cocktails hehe- I love both alcoholic and non-alcoholic mojitos in the summer! Your thriving mint made me crave one 😋
Glad you got the greenhouse set up, and that your sisters are happy to provide some extra plants to you. I think you're doing awesome, and it will just keep getting better!
I planted some garlic bulbs last autumn but I harvested too early this summer, I will know for next year now. I'll definitely be planting them again this year as I have lots of slugs around.
At the moment my garden has very low productivity plus the cold summer this year didn't help either, hopefully I can still grow something in the coming months