```python
from fastapi import FastAPI, HTTPException, Request
from fastapi.responses import JSONResponse
import asyncio
import helpers

app = FastAPI()


@app.post("/orders")
async def create_order(request: Request):
    try:
        order_data = await request.json()
    except Exception as e:
        raise HTTPException(status_code=400, detail="Invalid JSON payload")

    if not isinstance(order_data, dict) or "item" not in order_data:
        raise HTTPException(status_code=400, detail="Missing required field: 'item'")

    try:
        processed_order = await asyncio.to_thread(helpers.process_order, order_data)
    except Exception as e:
        raise HTTPException(status_code=500, detail="Failed to process order")

    return JSONResponse(content=processed_order, status_code=201)
```