How does stoichiometry relate to cooking?
The word STOICHIOMETRY comes from two Greek words, stoikhein which means element, and the metron* which means measure.
In the process of mixing elements in during chemical reactions the precision of measures of the reactants determines the expected outcomes of products.
This is often true in cooking. It is the precision of the measures of the ingredients the determine the expected outcomes of the food prepared.
Imagine if you were baking chocolate chip cookies and measured out your ingredients incorrectly. What if you added 2 tablespoons of flour instead of two cups of flour. Or if you added one cup of salt instead of one teaspoon of salt. Your cookies would definitely not be the hit of the next bake sale.
This is also true of chemistry and why stoichiometry is an important aspect of the chemical process. Balancing measures of the reactants involved to maintain the expected outcomes of the products desired.