
Be careful of oil splattering and handle the chicken hearts; it's quite troublesome.
Materials
Steps for making stir-fried chicken hearts (tender)

Thawing 1kg of frozen chicken hearts

Rinse the chicken several times to remove the blood. After thawing, add some hot water (optional) and prepare to process the chicken hearts.

The normal procedure is to make three cuts: one in the middle and one on each side. If you don't mind the extra work, flip it over and make four horizontal cuts. The white part around the chicken heart wasn't processed here because we eat it often and it's too much trouble. It generally takes about half an hour to remove the blood clots from 1kg of chicken heart. After processing, it will weigh approximately 0.75kg. Freezing and thawing will also result in some weight loss.

After processing, rinse the food several times with water, then add water and wine (I used 42º original liquor because I didn't have any cooking wine). Soak for 15 minutes.

Add water to the oil in a pan to skim off any foam. Heat the oil, then add some salt and vinegar (to soften the oil). Once boiling, add the chopped chicken hearts and cook for about a minute, depending on the size and quantity of the hearts. In the south, where the water temperature is higher, the cooking time can be shorter. I'm on the Loess Plateau at an altitude of over 700 meters, where the water temperature and gas stove aren't as good, so the cooking time is a bit longer (in winter).

Slice scallions, ginger, and garlic.

Take a handful of Sichuan peppercorns. The amount depends on how many chicken hearts you're processing.

Soak Sichuan peppercorns in hot water. The water should be hot enough to extract the flavor of the peppercorns.

Remove the chicken hearts, drain them, and if the water is still red, rinse them a few more times.

After draining the water, add the peppercorn water. Add salt and stir well.

Heat oil in a pan. Once the pan is hot, oil will coat the sides and accumulate at the bottom. Turn on the fan; at this point, the hot oil will produce smoke.

Add scallions, ginger, garlic, and Sichuan peppercorns. Be careful as the oil will splatter while frying. Once the oil is hot, remove all the ingredients and throw them in the trash. The oil temperature is high, so cool it down afterward.

Add the chicken hearts to the pan over medium heat, not one piece at a time, but in large handfuls. This will cause white smoke and oil splattering. Since the gas stove flame isn't very high, the chicken hearts started to simmer shortly after I added them. If the flame is higher, you might slightly brown each chicken heart. You need to estimate the simmering time based on the size of the chicken hearts; I simmered them for about 5 minutes. They were done in about an hour. After removing them from the pan, skim off the excess oil. The remaining chicken hearts are ready to be eaten. They don't have a strong fishy smell and are less flavorful than fried chicken hearts sold outside. You can dip them in fermented bean paste or chili sauce. Overall, they are quite tender.
Tips for stir-frying tender chicken hearts
Aside from having to watch out for oil splattering, the chicken hearts are a hassle to prepare.