What would be quality kitchen knives ?
You just asked a question that could lead you down a 10 year rabbit hole of exploration.
To simplify, it comes down to the quality of the steel, the blade shape and grind.
Do you want stainless? If so which stainless? Carbon? If so, which carbon? Do you want the blade mono steel or perhaps stainless clad or carbon clad? Quality factory or handmade? Do you want European or Japanese shaped knives? Maybe a Chinese cleaver?
And on, and on, and on...
