Translation:We had a gezellig conversation about frikandellen.
As a native English speaker with more than 30 years residence in Amsterdam, this sounds pretty good to me, and I will add it to my translator's toolkit of various ways to translate the supposedly untranslatable word "gezellig," depending on context. Hopefully DL will agree. I might however point out to beginners the difference between "a warm conversation" and "a heated conversation"!
I didn't try it, but would "chat" have been OK instead of "conversation"? It goes more naturally with "cosy/cozy". In fact, I would almost say: "a cosy chat" is something of a set expression in English, but: "a cosy conversation" is definitely not.
However, "a cosy chat" can also have a sarcastic or euphemistic meaning. If your boss says: "We need to have a cosy chat", he's almost certainly not meaning he wants to praise your work. He means: "We need to go somewhere private, so we can discuss what you did wrong!"
Similarly, to comment on others "having a cosy chat" could imply you think they are plotting something. It might be particularly true of people who are not naturally perceived as friends: "Look at those two, having a cosy chat! What are they up to?"
Or am I in paranoid mode tonight? ;)
een gesprek hebben = een gesprek voeren. In this case the construction 'hebben gevoerd' indicates that the conversation happened in the near past. If you eliminate 'gevoerd' you would be left with 'hebben', which indicates a conversation that is still going on. It works the same in English: have had vs have, it is not the same action.
Because it is basically the same thing. 'wij', however, is usually used to emphasize, whereas 'we' is the more general form of speech. For example: we left -- we zijn vertrokken; We are Billy and Daisy -- Wij zijn Billy en Daisy (corresponds to the question: And who are you? Whether it is asked or not); You want to go to London, but we want to go to Brussels -- Jullie willen naar Londen, maar wij willen naar Brussel; We want to go to Brussels -- We willen naar Brussel (WHERE do you want/wish to go?)/ Wij willen naar Brussel (where do YOU wish to go?)/Wij willen naar Brussel (where do you wish to go?)
So I'd suggest it is important to understand the differences and nuances, which doesn't mean it is wrong if you use the "wrong" form. It takes practice to master it properly.