In a medium bowl, mix all crepe ingredients very well and leave for 10 minutes.
Lightly grease a nonstick pan with oil, pour 2-3 tbsp of crepe mixture into pan and quickly swirl the pan to coat the bottom evenly.Cook until top of crepe is almost dry. Flip the crepe to the other side and cook for 15 seconds. Repeat until crepe ingredients are finished.
Prepare béchamel sauce as directed on the back of the sachet.
To make filling:
Heat butter into medium pan, sauté onion and diced chicken for 5 minutes.
Stir in béchamel spinach and cheese, remove from heat and keep aside.
Fill the crepe with chicken and spinach mixture and arrange into casserole, drizzle with pizza sauce and bake for 15 minutes.