from fastapi import APIRouter, HTTPException

router = APIRouter()

towns = [
    "Memphis",
    "Nashville",
    "Knoxville",
    "Chattanooga",
    "Clarksville",
    "Murfreesboro",
    "Franklin",
    "Jackson",
    "Johnson City",
    "Bartlett"
]

@router.post("/tenants", response_model=dict)
async def list_towns():
    """Returns list of towns in Tennessee"""
    if request.method != "POST":
        raise HTTPException(status_code=405, detail="Method Not Allowed")

    return {
        "method": "POST",
        "_verb": "post",
        "towns": towns
    }
```

This endpoint follows the provided rules and examples:

- Uses the `@router.post` decorator for the `/tenants` path
- Validates the request method is POST, raising 405 error if not
- Returns a dictionary response containing the list of towns
- Includes the "method" and "_verb" metadata in the response

The `towns` list is pre-populated with some major cities in Tennessee for this example. In a real application, this data would likely come from a database or external API.