async / await / task

await Task.WhenAll(eggsTask, baconTask, toastTask);
await Task.Any(eggsTask, baconTask, toastTask);
or with ManualResetEvent

namespace TaskThreadAwait01
{
	class Program
	{
		// https://docs.microsoft.com/de-de/dotnet/csharp/programming-guide/concepts/async/

		public class BaseCoffee
		{

		}

		public class PourCoffee : BaseCoffee
		{

		}

		public class Toast
		{

		}

		public class Eggs
		{

		}


		public class Working
		{
			public async Task Test()
			{
				PourCoffee cup = new PourCoffee();

				Console.WriteLine("coffee is ready");
				var eggsTask = FryEggsAsync(12);
				var toastTask = MakeToastWithButterAndJamAsync(20);

				var allTasks = new List<Task> { toastTask };
				while (allTasks.Any())
				{
					Task finished = await Task.WhenAny(allTasks);
					if (finished == eggsTask)
					{
						Console.WriteLine("eggs are ready");
					}
					else if (finished == toastTask)
					{
						Console.WriteLine("toast is ready");
					}
					allTasks.Remove(finished);
				}

				//Juice oj = PourOJ();
				Console.WriteLine("oj is ready");
				Console.WriteLine("Breakfast is ready!");            
			}

			async Task<Eggs> FryEggsAsync(int number)
			{
				Eggs myEggs = new Eggs();
				await Task.Delay(number * 1000);
				return myEggs;
			}

			async Task<Toast> ToastBreadAsync(int number)
			{
				Toast myToast = new Toast();
				await Task.Delay(number * 1000);
				return myToast;
			}

			async Task<Toast> MakeToastWithButterAndJamAsync(int number)
			{
				var toast = await ToastBreadAsync(number);

				ApplyButter(toast);
				//ApplyJam(toast);
				return toast;
			}

			public void ApplyButter(Toast toast)
			{
			   // await Task.Delay(number * 1000);
			}
		}

		static void Main(string[] args)
		{
			Working t1 = new Working();
			t1.Test().Wait();
		}
	}

Greetings Markus