Hi, there, JamieDoyle.

Ok, I'm drawing a complete blank on what "veg" is (an Author? a particular lowcarb Plan/Book?) but I can tell you that cheese, like most solids, is by weight so therefore are measured in either Grams or 'mass/avoirdupois' Ounces, not in Fluid Ounces which are volume measures.

So the mass Ounce is 16 to the Pound (old Imperial measure used in Canada before Metric, we don't use Stone) and 28.34 Grams each.

Like this:
Ounces -- Pounds ---------- Grams -- Kilograms
-- 1 -- -1/16th or 0.625 --- --28.3 -- 0.02834
- 16 -- -- 1 -------------- --454.0 -- 0.45400
-0.138 ---2.205 -----------1000.0----1.00000

Your 3 to 4 ounces is therefore approximately 85 to 113grams!