You get this moodlet by having an Over-Emotional sim who
first drinks nectar of perfect quality (90% Lifefruit, 10% Pomegranate) and
than eats Ambrosia, the quality of Ambrosia doesn't matter, but the fact that you must drink the nectar first and than eat your diner does. If you first eat and than drink the moodlet will be +98.
The Complete At Eas moodlet is a +98 when the sim is Over-Emotional. Just like the Ambrosia one this will last for 1 whole week.
Combine these two by first getting the Complete At Eas moodlet from the Spa and than drinking nectar and eating Ambrosia will give you a total of +201 for the next 7 days!
I challenge you now to get this sim unhappy.