using System;

using System.Collections.Generic;

using System.Linq;

using System.Threading.Tasks;

​

public static class Program 

{

    static readonly Random random = new Random();

    public static async Task Main() 

    {

        Console.WriteLine("START");

        var tasks = Enumerable

            .Range(0, 10)

            .Select(_ => new Task(() => MyMethod().GetAwaiter().GetResult()))

            .ToList();

        tasks.ForEach(task => task.Start());

        await Task.WhenAll(tasks);

        Console.WriteLine("END");

    }

​

    static async Task MyMethod() 

    {

        Console.WriteLine("#");

        await Task.Delay(random.Next(5));

        Console.WriteLine("*");

    }

}