You will find your pestle -- and other kitchen gear in industrial sizes! -- in the shops along Joo Chiat Rd and Onan Road. Go to where those roads meet Geylang Road (near the Malay Village) not at the Katong end. Start from Joo Chiat Complex and walk along Joo Chiat Rd, within 50yards you will start seeing these shops with all sorts of cooking utensils etc spilling out.
Singapore hawkers and restaurat chefs get their supplies from there. There are also "normal size" stuff but it is fun to browse and marvel at the gigantic woks, and paddle-sized stirring sticks.
There are also shops nearby which sell dried goods, spices, canned foods, pestos etc at wholesale prices. As I said that is where the cooking professionals shop. And not to worry you don't have to buy a half-truckload either.
And although off topic, although perhaps topical, there is a great doctor, Dr Chan in Joo Chiat Road. The many viruses and barking cough, blocked throat, sneezes etc are so difficult to shift. Some doctors give all kinds of tabs and their antibiotics do not work. This guy is brilliant. I usually don't consult a doctor but with my last two viruses, which were quite virulent, he treated me and the relief was apparent the following morning. Not a half dozen different tabs either. And about half the price of his neighbors too.
