Makes 1 x 600ml bottle
1 tbsp olive oil
1 brown onion, diced
1 tsp chopped garlic
1kg Roma tomatoes (or 500g tomatoes plus 1 can of tomatoes), halved
1 tsp chilli flakes
2 tsp sea salt
¼ cup apple cider vinegar
½ cup brown sugar
Grind of pepper
½ tsp celery salt
1-2 tsp bicarbonate of soda, if required
1. Before you start, you should sterilise your glass bottle. To do this, you can put your bottle on a hot cycle in the dishwasher or, alternatively, wash with hot soapy water then place on a rack in the oven (set to a low temperature) for 10-15 minutes.
2. Heat the olive oil in a frying pan then add the onion. Stir fry for a few minutes then add the chopped garlic.
3. Heat the onion and garlic for another couple of minutes then add the remaining ingredients, except the bicarbonate of soda – only add this if you find the sauce too tart at the end.
4. Bring your ingredients to simmering point and allow to simmer gently for 30 minutes.
5. Take off the heat and allow to cool for 20 minutes. Then, blend the sauce and strain back into the saucepan.
6. Heat for a further 15 minutes or until the sauce reaches the desired consistency. Taste as you go and adjust the seasoning as required. You can now add bicarbonate of soda if needed - this neutralises acidity, so can be added a little at a time to reduce tartness.
7. Strain your finished sauce into the bottle and leave to cool. This homemade tomato sauce keeps for up to four weeks in the fridge and tastes incredible with sweet potato fries fresh from the oven.