It does seem like a lot of work to set up products, inventory items, and then recipes. But any Inventory system for a Restaurant is going to have this level of complexity and is going to take a lot of time to implement properly since “most” Restaurant items are not 1:1 mappings, except for maybe canned/bottled beverages.
A Cheeseburger (Product) is made of (Recipe):
1 bun
8oz ground beef
Seasonings
Slice Cheese
Produce (slice Lettuce, slice Tomato, slice Onion, etc)
Condiments (1ml Ketchup, 1ml Mustard, etc)
You buy (Inventory):
12 pack buns
10 lbs ground beef
various seasonings
Case Cheese
Pounds, ounces, or other quantities of vegetables
Gallons/Litres of each condiment
If you have more of a retail-oriented business, then use the Bulk Importer in this case. It will map Products to Inventory Items to Recipes if you define your CSV file properly. JohnS originally designed it for this very reason - using SambaPOS for Retail 1:1:1 mappings. His example DB even shows this clearly for selling car parts and labor.
See further in the thread for updates and improvements by myself.