1. Cut the avocado in half lengthwise and remove the pit, cutting it into bite sized pieces inside the skin. Use your fingers or spoon out the avocado pieces into a plastic bowl, add the lime juice.
2. Cut tomatoes in half, dicing the red onions and adding to the mixture.
3. Into a small bowl, add the cumin, seasoning and sea salt with a twist of lime juice, whisking in olive oil a little at a time until the dressing is completely coated. Pour this dressing over the avocados and stir gently to combine. Taste to check for seasoning and then add a little more sea salt if required.
4. Serve straight away or alternatively, save for leftovers and place in the fridge overnight until the next day.