The kitchen and the living room are in the same room. For making a separation i put some trunks in the floor. What i learned here, is that it is better to put first the concrete, and then the trunk, and not the other way round, to get the bottom completely covered.
The technic is similar as the walls of the house where made. The difference is one layer, and wood instead of concrete or steal columns. This worked quite well.
We put behind plywood, but also carton works if you put it double.
smear it ...
The final result, after putting some nice decorative bricks in front.
... and from inside.