Much to his.... (amazed), he saw a large bear walking towards him.
Much to his amazement, he saw a large bear walking towards him.
Much to her... (amused), she saw a very weird clown.
Much to her amusement, she saw a very weird clown.
Much to my... (determined) to finish the race, I hurt my ankle during the final kilometer.
Much to my determination to finish the race, I hurt my ankle during the final kilometer.