SitecoreHelperExtension.cs

using Sitecore.Mvc.Helpers;
using Sitecore.Mvc.Pipelines;
using Sitecore.Mvc.Pipelines.Response.RenderRendering;
using Sitecore.Mvc.Presentation;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Web;

namespace SUGCON16.Extensions
{
    public static class SitecoreHelperExtension
    {
        public static HtmlString ControllerRendering(this SitecoreHelper helper, string controllerName, string actionName)
        {
            var rendering = new Rendering()
            {
                RenderingType = "Controller"
            };

            rendering["Controller"] = controllerName;
            rendering["Controller Action"] = actionName;
            rendering["Cacheable"] = "1";
            // Cache_VaryBy...
            // Datasource

            var writer = new StringWriter();
            var args = new RenderRenderingArgs(rendering, writer);
            PipelineService.Get().RunPipeline("mvc.renderRendering", args);
            return new HtmlString(writer.ToString());
        }



    }
}