When a recipe calls for broth, you can accomplish this in one of three ways:
Broth
You can use canned or boxed broth in the amount the recipe calls for.
Base
You can use chicken, beef, or vegetable base. To accomplish this, use water in the amount of broth the recipe calls for combined with 1 tsp base for each cup.
This is a versatile method as you can use 1/2 cup water : 1/2 tsp base; 1/4 cup water : 1/4 tsp base, etc, to get amounts that are not full cups.
Bouillon
You can use chicken, beef, or vegetable bouillon. To accomplish this, use water in the amount of broth the recipe calls for combined with 1 boouillon cube for each cup.
This method does not allow for partial cup measurements. If a recipe calls for a partial cup, prepare the next full cup larger than what is called for and discard the remainder – or save it for another recipe.