how do I make a regular pea puree without it being super starchy

Frozen sweet or petite peas are much less starchy than "fresh" peas that are not perfectly fresh.

I've found that it sometimes helps to add a little cream. It (obviously) thins the puree a bit and cuts the starch factor.

I would cook the peas in lots of salted boiling water until just tender. Immediately put them in a ice bath to keep them green. Rather than putting them through a blender or food processor, I would puree them with an old fashioned food mill. If you don't have a fine blade, you could then press through a fine sieve or China cap.