There might be a separate section (as in separate from the soup products) in your supermarket for “Knorr” products. Knorr makes seafood stock bouillon cubes. Look in the pre-made sauce area for this. Alternatively, go to an Hispanic market and look for Knorr seafood bouillon cubes. They’ll have an illustration of a red shrimp on the package. When you find it, stock (heh) up on a few boxes.