Hi, I am new to this community so pardon me if I haven't posted this in the right place and direct me to the correct forum.
A slate tile has been broken into 3 pieces in my front patio and the broken tile has large gaps and doesn't fully fit in the area.
Here are the pictures with and without the loose tiles:


The size of this area is 180mm x 150mm and it is roughly about 8mm deep.
Since these slate tiles are hard to get nowadays, I was wondering what is the best way to fix this:
1. Glue the tile and use gap filler or
2. Remove the broken tiles and just fill the void with mortar or something else