gistfile1.cs

internal class Program
    {
        private static void Main(string[] args)
        {

            var myClass = new ExpressionTest();

            // Ambig.
            myClass.TestMethod(myExpression1:x => x.ToString());

            //myClass.TestMethod();

        }
    }

    public class ExpressionTest
    {
        public void TestMethod(Expression<Action<int>> myExpression1)
        {
            
        }

        public void TestMethod(Action<int> myExpression2)
        {

        }

        /*public void TestMethod(Action myExpression)
        {

        }*/
    }