Malabar Spinach Red Stem

This plant is called Malabar Spinach Red Stem, it was very easy to grow so far, it came up in a matter of days and has a very thick and heavy stem and huge leaves.

I want to plant it in a container and keep wondering if it is best to go ahead and put each plant individually in a peat pot until it is a real plant or go ahead and put several in a large pot to grow right now.

It is supposed to look like this when mature:

It is an edible plant that tastes like spinach but really isn't spinach.

Any advice that would help me make my plants look like the one in the second picture would be greatly appreciated.