One of the easiest sauces I've learned from my best friend in culinary school, Tomomi Fujimoto (who now has a popular restaurant in Kyoto), is Teriyaki Sauce. She taught me this sauce one gloomy winter afternoon in London, as we laughed the cold away, by eating something grilled - otherwise known as yaki. This simple recipe may be used as a tare (marinade).
Use a tablespoon of soft brown sugar and place it in a saucepan.
Add 5 tablespoons of Sake.
You may opt to remove this ingredient if you're worried about the alcoholic content for your baby. Chefs told me in culinary school that it disappears during cooking but, after several discussions with the food chemists I've worked with, they say it's tricky business (plenty of variables to consider from cooking temperature, cooking time, lid on or off during the process, etc. etc. - you get the picture).
Add 5 tablespoons of Mirin.
Add 5 tablespoons dark soya sauce (please use Japanese made).
With a whisk, mix under medium heat until the sugar dissolves completely. Bring to a boil.
Then remove from the stove.
This Teriyaki sauce is highly recommended for fish and chicken (we cooked ours with supreme and thigh fillets), use immediately or allow to cool then bottle. Keep refrigerated.