Seal between brick --> wall

[Naimiez]

I have a brick inner wall that I want to seal in a nice way. What to use?? Currently, I have jigsawed chipboard, but it's not tight and nice. Tips?? Some form of foam and then latex??

 

[Peter2400]

What are you going to cover the chipboard with then?
I would have carefully filled the gap with foam, as you said, buy a gun and a loose bottle, single-use bottles don't work for small jobs.
Then I would have caulked with a good paintable soft joint sealant, e.g. Tec7.