"We were shocked and felt quite lost at first," she recalls.
The couple began making trips to Australia to source for suitable produce for Ryan. Over three years from 2010, they visited farms and farmers' markets there to find out more about the producers and their products.
Ms Foo began talking to the farmers about exporting their items here.
Ryan's Grocery was launched in July 2015. The retail store in Binjai Park is a one-stop shop for anyone looking for allergen- and preservative-free food, and includes a selection of organic, hormone- and antibiotic-free meat sourced from farms in Australia.
The couple also launched Alternative Selection - a wholesaler and retailer of alternative gourmet products - last year.
Response to Alternative Selection has been good. It now supplies to more than 100 cafes, restaurants and hotels in Singapore.
The company employs close to 40 staff, but the business has not broken even yet, because of the expansions over the past two years.
Ms Foo says she hopes it will be able to do so by the end of this year.
In the works are plans to supply meat to major supermarket chains here.
"People here increasingly want to eat well and want to know where their food is coming from. We want to give people that access to quality produce," she says.
What is your take on food?
Food is more than just for filling our stomachs or tasting good. I believe that food contains healing properties. Instead of medication, I turn to food to help Ryan's leaky-gut syndrome. I boil beef or lamb bones to make broth for him.
Food is also a way to show love to my loved ones.
Do you enjoy cooking?
Yes. I find it therapeutic and de- stressing. I love experimenting with allergen-free recipes for the family. My kids love my tomato vegetarian pasta sauce and braised pig trotter with coconut amino acid (which I use in place of soya sauce as my son Ryan cannot take soy).
Do you like to make things from scratch?
Yes. I can create my own mushroom sauce, tomato sauce and pork floss. I also make pumpkin seed bars, banana, quinoa and buckwheat bread, and chocolate - made from organic cocoa powder, blueberries, agave syrup and dairy-free butter.
Is there any raw food item that you do not enjoy working with?
I used to hate garlic and could not eat any dishes with it until I was in my late 20s.
The aversion began after I helped out with food preparation for family gatherings when I was younger. I used to have to peel and chop the garlic and the smell of it would stay on my fingers. However, after having a mantis shrimp dish in Hong Kong in my late 20s, which I later learnt had a lot of minced garlic in it, I became a fan.
What is one of your favourite restaurants here?
Summer Palace at Regent Hotel. It has a gluten-free menu and can provide a Chinese meal according to Ryan's dietary requirements.
What is one surprising item you found on your product-hunting trips in Australia?
Food manufacturer Ayam Brand's range of gluten-free sauces. These were carried only in supermarkets there. Ryan's Grocery carries them now.
You spent 12 years working in Hong Kong and China. What are some exotic dishes you've eaten there?
I love snake soup with chrysanthemum petals in Hong Kong, which I have during winters there. I have also tried deep-fried scorpion in Beijing and seaworm jelly in Xiamen. The locals told me that the slimy worms are protein-rich and can strengthen one's immune system.
What are some misconceptions that people have about red meat?
People assume that red meat is high in cholesterol and that it is healthier to eat white meat.
However, organic beef, for example, has high amounts of minerals such as calcium, zinc, iron and magnesium. It also has higher levels of omega-3 fatty acids, which can help to lower bad cholesterol levels.
What is a must-have item at your family dinners?
Soup, which I boil for at least four hours. My favourite is a clear chicken soup with fresh coconut.
Mattheus' favourite soup is watercress with water chestnut and honey dates, while Ryan enjoys apple soup with pork and figs.
If you could invite anyone to a meal, who would you choose?
I would love to invite my father. He died in the late 1980s. He used to take us to new eateries every weekend.
Once, I was sitting in a small room in an eatery in Beijing, having a charcoal hotpot dinner with Chinese wine. It was snowing outside. This is a meal I wish to share with him.