Hi *|CONTACT.FIRSTNAME|*,

I am [Your name] from [Company name] . It was a pleasure chatting with you last time. Following up on our chat about [product/service]. Your thoughts were awesome. 
I've put together a quick plan (see attached) on how [Your Product/Service] can help with the stuff we talked about. Can we catch up next week for a quick chat to discuss? 

Looking forward to the opportunity to collaborate.

Best regards,
[Your Name]