Soy cannot be eaten by humans unless fermented as tofu, miso or tempeh. It lines gut with plastic. They make plastic out of soybeans, you know. Baby an have seasoned tofu, as a food, though, in place of meat. This recipe for baby formula using goat's milk came from a great European healthfood doctor who charged thousands to his clients.
Gruel is a thickened cereal broth.
You boil cereals, they make creamy brown gruel. Make a whole cup of cereal powder and keep it in fridge in closed jar. Stir in 2 tbsps of powder, boil at low simmer, in good, clean water until it's thick like cream. You'll get about a cup of gruel. Use l tsp sweetener.