Start by placing the chocolate in a bowl and melt it in the microwave in 30-second intervals, until fully melted. If you don't have a microwave, you can do it in a double boiler, just transfer it to a larger bowl.
Add the condensed milk and the peanuts, mix it all together very well until combined.
Now, line a baking tin with plastic wrap and transfer all this candy to it, evenly spreading it out.
Take the baking tin to the fridge and let it chill for 2 to 3 hours.
Unmold on a plate and cut the candy into equal-sized pieces, making several candy squares.
Serve and keep in the fridge.