Nested partial output caching in ASP.NET MVC 3

I am using Razor view engine in ASP.Net MVC 3 RC 2. This is part of my view city.cshtml

(drastically simplified code for the sake of simplicity in example)

<!-- in city.cshtml -->
<div class="list">
@foreach(var product in SQL.GetProducts(Model.City) )
{
  <div class="product">
    <div>@product.Name</div>
    <div class="category">
    @foreach(var category in SQL.GetCategories(product.ID) )
    {
      <a href="@category.Url">@category.Name</a> » 
    }
    </div>
  </div>
}
</div>

I want to cache this part of my output using OutputCache attribute, so I created an action ProductList with OutputCache attribute enabled

<!-- in city.cshtml -->
<div class="list">
  @Html.Action("ProductList", new { City = Model.City })
</div>

and I created the view in ProductList.cshtml as below

<!-- in ProductList.cshtml -->
@foreach(var product in Model.Products )
{
  <div class="product">
    <div>@product.Name</div>
    <div class="category">
    @foreach(var category in SQL.GetCategories(product.ID) ) 
    {
      <a href="@category.Url">@category.Name</a> » 
    }
    </div>
  </div>
}

but I still need to cache the category path output on each product. so I created an action CategoryPath with OutputCache attribute enabled

<!-- in ProductList.cshtml -->
@foreach(var product in Model.Products ){
  <div class="product">
    <div>@product.Name</div>
    <div class="category">
      @Html.Action("CategoryPath", new { ProductID = product.ID })
    </div>
  </div>
}

But apparently this is not allowed. I got this error:

OutputCacheAttribute is not allowed on child actions which are children of an already cached child action.

I believe they have a good reason why they need to disallow this. I really want this kind of nested Output Caching.

Any idea for a workaround?