Otherwise known as tomato puree.
Spoon out heaped tablespoons of leftover tomato paste onto pieces of cling film. Twist the ends of each section like a candy wrapper and store in the freezer.
Throw a ball of tomato paste into whatever you’re cooking, straight from frozen. You’ll never throw out half a tin of tomato paste again.
Caroline Feeds 
Great tip! I always end up throwing most of it away.
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