Here it is!
First, I searched online for how-to, recipes, ideas, etc.
Then I tried to find the ingredients.
Not easy...like a recipe from a cookbook, it's hard to find all ingredients here.
Finally the recipe was something like cement+perlite+sand+dried&sifted peat based mix.
Then, the problem was with the mold. I used wood boards etc.
Then I mixed the mix, then carefully made the troughs... a small problem was the walls kinda separating from the mold and leaning inside.
Well, the final result was OK... I am pleased!
After patiently waiting for a few weeks I got them out of the molds, filled them up with a mix rich in gravel and some perlite and then skillfully and artistically planted the sempervivums.
Thinking I still have some space left, I added some Thlapsi stylosum and some cute Sedum. And of course pebbles, rocks, stones :)
Here's the metal bad my brother gave me for... support.
He also helped me drill the holes for the screws.
Here's the BEFORE pic, with the potted Sempervivums.... waiting for a nicer, cozier home.
Here's the view from my kitchen with the troughs already fixed.
And the AFTER pics!