One Day in Quito
We lived in Quito (including my older daughter who's a corporate litigator as is her husband - what's going on here?) for a couple of years and then had an Ecuadoran housekeeper here in the US.
Since I assume you are foodies, the local food will seem very, very plain and monotonous to you. Some of it will seem terrible and if you are not really careful, you can get sick easily. Once you actually live there, the food becomes a series of fascinating lessons in the history, culture, and climate of one of the most diverse countries in the Americas.
If you are in Quito for only one day, La Choza serves la comida tipica or the local food. Las Redes is a seafood restaurant that has simple preparations of local seafoods. Both have been around for a long time.
If you have more time, Hosteria La Mirage near Otavalo is where we always stayed and ate. Hosteria La Cienega about 50 miles south of Quito on the slopes of the Cotopaxi volcano is close and a nice drive for lunch. Both are beautiful and have good food, typical of the Andes.
If you are going to eat only a few things, the most typical main course would be fritada - essentially pork fried in its own fat (gasp!) - which is absolutely delicious. This is what you see all those street vendors selling and it is virtually the national dish, almost like our hamburger. It is served with onions, shreds of lettuce and tomato, and often mote (hominy.) There is always a bowl of aji on the table. This condiment is made of very hot chilis with tomate de arbol (tree tomato? whatever that is) which is made fresh every day and Ecuadorans put it on everything.
A wonderful and commonly served soup is locro, made from potatoes and fresh cheese. The favorite empanada is empanada de morocho for which the pastry is made from a specially treated corn - I was never sure if it was fermented or what because we bought it already prepared.
Ceviche is also generally available and there are several kinds, served with popcorn as a garnish - weird, but we grew to love it that way. The most common fish is corvina, known to us as Chilean sea bass. It makes great ceviche. A hard to find local delicacy is cuy (guinea pig) which is usually spit-roasted whole.
Although life is changing somewhat, many people still eat their largest meal in the middle of the day because the altitude makes digestion difficult. Quito is above 9000 feet.
Consequently they have a merienda at about 5 PM and the favorite snack is the humita, a faintly sweet tamale. This is served with coffee. Things may have changed but coffee was just bad in the entire country except for the places that catered to foreigners. The local black pepper was of poor quality and I carried my own small pepper mill. (I guess everyone has one princess flaw.)
Be very, very careful about what you eat and drink. Fruit juices are often mixed with water. Many things are not washed well if at all, including hands.
It is a beautiful country with wonderful people. We loved it there and I adored the food once I got to understand the roots. I'm sorry you'll have so little time.
Susan, since you'll have 3 days, you might enjoy the big public market - especially if you speak some spanish.
I wish I were going with you! The Galapagos is like nothing else I've ever seen.