Cooking
From A KoL Wiki
Cooking is the fine art of mixing drinks. Mixing drinks always results in a drink that is better than the ingredients used to make it.
You cannot mix your own drinks unless you have an E-Z Cook Oven in your inventory or either a chef-in-the-box or a clockwork chef-in-the-box installed in your campsite. An E-Z Cook Oven allows you to cook one dish at the cost of one adventure, while a boxed chef allows you to cook one dish for zero adventures. However, your chef will explode after a certain number of turns and you'll have to build a new one.
To cook meals, go to your inventory and click on cook stuff.