overchar

verb

Infinitive:  overchar
3rd person:  overchars
Present:  overcharring
Gerund:  overcharring
Past:  overcharred
Perfect:  overcharred 

To burn too much;  to brown or blacken the surface of food beyond the desirable level;  to scorch or carbonise.

Examples:

If it's impossible to proceed without auxiliary flour and heneggs, the culprit almost certainly is the potatoes:  Only concoctions comprising unsuitable varieties will crumble or overchar.  (Source: J∙ Okram - Bartonian Potato Pancakes  ●  Cooking Recipe.)