🚀 go-pugleaf

I have two tables T_PRODUCT_GENERAL and T_PRODUCTS_COMPOSITION.
The idea is that a products can consist of subproducts which in return can consist of subproducts ...

for example if i have a menu called "Steak with Peppersaus"
it's composed out of Steak and Peppersauce.
The peppersauce consists out of Pepper, flower, ...

So basically i want a stored procedure.
SP_PRODUCT_COMPOSITION(Steak with Peppersaus, 1) which returns
Steak, Pepper, flower, ...

RECREATE PROCEDURE SP_PRODUCT_COMPOSITION (
 IN_PRODUCTID        INTEGER,
 IN_PRODUCTQUANTITY  NUMERIC(8,2))
RETURNS (
 OUT_PRODUCTID       INTEGER,
 OUT_PRODUCTQUANTITY NUMERIC(8,2))
AS 
BEGIN
  ???
END

CREATE TABLE T_PRODUCT_GENERAL (
  PG_PRODUCTID      INTEGER NOT NULL,
  PG_PRODUCTNAME    VARCHAR(80),
  PG_PRODUCTPRICE   NUMERIC(8,2),
  PRIMARY KEY (PG_PRODUCTID)
);

CREATE TABLE T_PRODUCT_COMPOSITION (
  PC_COMPOSITIONID       INTEGER NOT NULL,
  PC_PRODUCTID           INTEGER,
  PC_SUBPRODUCTID        INTEGER,
  PC_SUBPRODUCTQUANTITY  NUMERIC(8,2),
  PRIMARY KEY (PC_COMPOSITIONID)
);

Any help would be appreciated.

Olivier Peter