The recipe of a product is the total of the ingredients and the related quantities to produce a finished product.
The configuration of the recipe depends on the type of product, as follows:
if the configured product is "I sell it as I buy it" you will be able to add a single good
if the configured product is of the "Contains recipe" type, you will be able to add more raw materials.
if the configured product is of the "Service" type, you will not add any stock to the recipe.
More details on the type of products can be found in this article.
In conclusion, you have to be very careful on how you make your recipe, because if it is done wrong, your stocks will not decrease properly once you sell your products.
Click here for details for when you have a negative stock.
This section is nothing more than a subtraction operation: how much quantity from a good do you want to subtract when selling a product.
Click here for details on how does the stocks decrease in Stock Management at sale.