This is satin stitch with a little embossed or dimensional look. This is because we first give the pattern a little padding at the base before doing the satin stitch. I will  illustrate this stitch using a leaf pattern.

You need to know any basic straight line stitch like chain stitchoutline stitch , or  back stitch, to do the outlining. You also need to know the satin stitch.

padded_satin_stitch_1   padded_satin_stitch_2
Fig 1: First, stitch an outline of the pattern to be done. I have used chain stitch to outline, but you can use any straight stitch like the back stitch or the outline stitch.   Fig 2: Once the outline is done, fill the inside of the pattern with straight stitches. You can fill it up with chain stitch too. The idea is to give a padding for the satin stitch that we will be doing, so we need not make this stitch to cover the pattern entirely.
padded_satin_stitch_3       padded_satin_stitch_4
Fig 3: Once that is done, do the satin stitch to cover the pattern. The needle needs to go in and out of the fabric from outside the chain stitch.   Fig 4: The completed pattern will look like this.  😀