This sprouted in one of my pots where I sowed seeds last spring, as i didn't know what it was I potted it up in its own pot, now it has grown a lot, and I still don't know what it is, certainly not something I intentionally sowed!
The leaves are rather big and smooth and have no scent ..

It looks like Iochroma, but I can't imagine it growing from seed in Belgium...
probly a nicotiana.

Thanks for the suggestion Stone! If it is an Iochroma, that would be interesting, but like you say, unlikely, as it not growing over here being a tropical.
I did sow some seeds I collected from my trip to Brazil, what came up were some Begonias, Cosmos caudatus and Canna indica..but i also sowed other non- Brazilian seeds, forgot now in what seed pot i found the volunteer..
Would the leaves of a Nicotiana sp. not have a scent when rubbed ? mine really have none..

Some more info...

It kind of looks like a young Pokeweed (Phytolacca americana) to me.

I also had thought about Pokeweed Dave, though native American, it is also grown over here, I know my father used to have them in his greenhouse ( self-set) and occasionally in the garden too, but that is many years ago..

I have also been thinking of a sweet pepper plant (Capsicum).. you know those big ones..I remember they have big leaves, I sometimes saw them for sale on the flower market or a supermarket as a plant, never bought one though, so am not so familiar with them..
I often buy and use the peppers though..

I was going to suggest Capsicum Myriam, but you already have.

https://www.google.co.uk/searc...

yes I think Capsicum is the best candidate Janet. I hope to get flowers to be sure..
The leaves of this Capsicum praetermissum look very much like it..
https://www.google.be/search?q...
and when I see the peppers of it:
https://www.google.be/search?q...
These look very much like the little chilly peppers I've seen growing in Brazil, also in the wild..so maybe it hitchhiked ..

Do you have any Basella alba seeds? I am only making a guess but could that be a possibility?

Thanks, but no Greene, I've never had Basella alba seeds, I've googled the plant and its leaves look heart-shaped, not like mine..

It sure looks like poke weed.

My first thought was that it reminded me a bit of Phytolacca too but the more I look at the pictures, the more I'm leaning towards Capsicum.

P. americana
http://www.pestid.msu.edu/wp-c...
http://www.pestid.msu.edu/wp-c...

P. acinosa
http://alienplantsbelgium.be/c...
Indian Poke (Phytolacca acinosa)

It looks a lot like Capsicum annum: http://www.bing.com/images/sea...
http://www.bing.com/images/sea...

Thanks Lin, interesting site you found of the 'alienplantsbelgium'!
It could be Capsicum annum, but I guess many other Capsicum sps have similar leaves, I'll just have to be patient to get the first flower and maybe fruit..