There is actually a simple approach in the A-share market: just look for targets listed as A/H shares.

If the H-share premium (H-shares valued higher than A-shares) exists, it definitely indicates a good company, even an outstanding one.
Because H-shares generally have lower liquidity and other disadvantages compared to A-shares, and most foreign investors do not recognize Chinese assets, H-shares are usually at a discount.
So, when you find a target with an H-share premium, it must be a core asset.
For example, CATL, for instance, Zijin Mining.