How to make symmetrical wavy lines and/or a circle with a symmetrical wave?

I'm trying to copy the shapes of this broccoli. I thought I could do it by overlapping circles, but that didn't work. I then tried to draw a wavy line with the pen tool and replicate it. That also didn't work. The distort tools seem to add the distortion in a random way, so I couldn't work out how to do it that way, either. 

When I google this, I keep getting the reflect tool, so I thought I'd ask here:

How can I either make a line with a regular repeating line and/or how can I make a circle with a regular wave like in the attached photo? 

Thank you,