Add mesh with materials to scene through code.

I'm writing a MenuItem that iterates through fbx files located in "Assets/Resources". I want it to add one instance of each mesh to the current scene.

From helpful posts I have learned how to generate a GameObject and add a MeshFilter and MeshRenderer etc. But what I really want is for the GameObject to be generated as if drag-and-dropping the mesh from the asset browser into the scene [which means materials are assigned correctly].

Is that possible?

If not - how can I query for what materials a mesh is referencing?

Current code [that works but not giving me the result I am after]:

 using UnityEngine;
 using UnityEditor;
 
 using System.IO;
 
 public class MenuItems
 {
     [MenuItem("Tools/Process Meshes")]
     private static void NewMenuOption()
     {
         DirectoryInfo directoryInfo = new DirectoryInfo("[some unity project path]\\Assets\\Resources\\Meshes");
         FileInfo[] fbxFileInfos = directoryInfo.GetFiles("*.fbx");
         foreach (FileInfo fbxFileInfo in fbxFileInfos) 
         {
             string meshResourcePath = string.Format("Meshes/{0}", fbxFileInfo.Name.Replace(".fbx", ""));
 
             var mesh = Resources.Load(meshResourcePath, typeof(Mesh));
 
             Mesh meshInstance = Object.Instantiate(mesh) as Mesh;
 
             GameObject gameObject = new GameObject(fbxFileInfo.Name.Replace(".fbx", ""));
             gameObject.AddComponent(typeof(MeshFilter));
             gameObject.AddComponent(typeof(MeshRenderer));
             MeshFilter meshFilter = gameObject.GetComponent("MeshFilter") as MeshFilter;
             meshFilter.mesh = meshInstance;
         }
     }
 }