How to return nested list from html forms usingf pydantic?

Trying to return form data in a nested list. Current code returns the below format:

{
   "name":"meal number 4",
   "description":"new description",
   "ing_qty":"4",
   "ing_type":"small",
   "ing_name":"Tomato",
   "ing_id":"9"
}

Printing raw FormData results in:

FormData([('name', 'meal number 4'), ('description', 'new description'), ('ing_qty', '4'), ('ing_type', 'small'), ('ing_name', 'Onion'), ('ing_id', '6'), ('ing_qty', '4'), ('ing_type', 'small'), ('ing_name' , 'Red'), ('ing_id', '7'), ('ing_qty', '4'), ('ing_type', 'small'), ('ing_name', 'Tomato'), ('ing_id', '8'), ('ing_qty', '4'), ('ing_type', 'small'), ('ing_name', 'Tomato'), ('ing_id', '9')])

I am trying to get the results into the below format so that i may update my db recrds with the form data.

{
   "name":"string",
   "description":"string",
   "ingredients":[
      {
         "ing_id":null,
         "ing_qty":null,
         "ing_type":null,
         "ing_name":null
      }
   ]
}

Here are my Pydantic BaseModels

class IngUpdate(BaseModel):
    ing_id: Optional[int]
    ing_qty: Optional[int]
    ing_type: Optional[str]
    ing_name: Optional[str]


class RecipeUpdate(BaseModel):
    name: Optional[str]
    description: Optional[str]
    ingredients: List[IngUpdate] = []

Here is my Post Request:

@router.post("/edit/{recipe_id}")
async def edit_select_recipe(request: Request, recipe_id: int,
                             db: Session = Depends(get_db)):

    data = await request.form()

    print(data)
    return data

Adding Response Model to Post returns the following result:

{
   "name":"meal number 4",
   "description":"new description",
   "ingredients":[
      
   ]
}

It appears it's unable to pull the data into a list. How can I get this into a nest model?