Jiaozi potstickers sticking to fry pan

Your problem is probably between steps 3 and 4. When the oil is rippling, it is developing ridges and troughs of varying thicknesses of oil. The troughs, or thin spots are the most likely culprit for sticking.

After the oil has started to ripple, turn the heat down and tilt the pan so the ridges and troughs in the oil start to even out, then add the potstickers. Wait for a minute or two before turning the heat back up.

You can use a lower fire when frying to avoid sticking. After it's fried, let it rest in the pan with the fire off.

Or use a nonstick pan.

These answers have touched on your solution. An even layer of oil is good because you wont let the edges touch the hot pan, where the oil is shallow. But also, another thing you can try is to cook the pot-stickers from non-frozen and/or bake them for a few minute and then fry.

If you choose to keep your current procedure, when the oil ripples, grab the pan handle (with a hot pad) and shake gently back and forth to evenly distribute the oil. This often gets rid of the ripples and allows for even depths. I would recommend experimenting with different techniques, though, like thawing first and/or baking or nuking for a few minutes before frying.

How are these pot-stickers made? From scratch or from a bag? If there are instructions, what are they?

I sometimes get the individually frozen potstickers and I use the inverse procedure. I fry each one in medium heat until you get the brown bottoms and then I add the water (or stock) to the pan.

Food likes to stick to metal, that is why cast iron pans need to be seasoned. In stainless steel the oil is supposed to get into all the microscopic crevices in the pan, but this does not always happen.

I know it dirties one more pan, but the two-step method is better for potstickers:

1. Boil the potstickers the specified time (usually around 8 minutes)
2. Heat up a pan on high, add the oil, fry the pot stickers.

As much as I love olive oil, for frying things on high heat, you can't use it - it'll be burning. For potstickers, fried rice, stir frying vegetables, I use grapeseed oil. And unless you're doing just a few potstickers, I'd use more than 2 tablespoons.

You want perfect potstickers?

Steam them first, you may need parchment paper or cabbage or oil underneath so they don't stick.

Then sear on high heat for color, with oil. Thats how restaurants get this perfect dumplings.

I know this is an older question but here is a method I developed over the years:

I use nonstick pans but I‘ve done it also in stainless. I use a small amount of oil and warm it to thinly cover the pan bottom. I add the potstickers, tight but in a single layer, and cover with hot water about 2/3 of their height. I bring it to a boil moving the pan slightly back and forth just to move the potstickers in it. I do not use lids. I boil them, turning them halfway and moving the pan regularly to not let the dumplings settle and stick.

I continue until the water nearly evaporates and slimy dough residue starts showing in the pan. I increase the heat and now I move the pan in a circular motion until the potstickers “pick up” all the dough slime. After a minute or two the dumplings sit in clear oil (just coating the surface). I sear them on three sides until they start showing crispy surface.

I use 2 pans simultaneously to make about 30 potstickers. This method requires staying nearby pretty much the whole time (once they are frying you can step away as they will no longer stick but you still have to watch the browning). The dumplings are soft and juicy on the inside and crisp on the outside. After using several other methods I settled on this one and my diners love it.

(I understand my answer is broader than the narrow question of why the sticking problem recently emerged with a stainless pan. Recent scratches in the pan may be the cause but I found that moving the pan and making the potstickers slide prevents the sticking even in pans than no longer have perfect surfaces, stainless or nonstick).

Please, all pot stickers should first go into hot oil for 1-2 minutes to get the browning that will create your Sticky, Crispy bottom. As soon as you can sense the browning is right, you could peek at one, add enough Chicken Stock to steam covered for 4-5 minutes. Remove cover and let all remaining liquid evaporate, tilting pan to keep liquid in contact with pot stickers. When evaporated, pot stickers are ready. They will now have a caramelized bottom that is far more flavorful than any you've had prepared without the stock! you will need to remove them from the pan carefully with a metal spatula, but it is so worth it!
Happy dining!