Preheat oven 200°C or 400°F. Cut red onions in half lengthwise with skin on and place cut side down in oven tray. Drizzle with olive oil and season with salt. Roast in oven for 30-40 minutes until soft and brown.
Remove from oven to cool. Then slice approximately 1cm thick lengthwise (from top to root).
Preheat grill to medium-hot heat. Coat corn with olive oil and season with salt and pepper. Place on grill and cook for 15 minutes or until well charred. Remove from grill to cool.
Stand corn on its bottom, hold the tip, then using a sharp knife and cut corn from cob by running knife from top to bottom.
Wash and cut tomatoes lengthwise.
Cut avocado in half with skin on and remove pit using teaspoon. Peel skin off and place avocado cut side down. Then cut into cubes, place in a small bowl and squeeze lemon juice to stop the avocado from going brown.
Wash and tear up coriander leaves.
Mix olive oil, lemon juice, dijon mustard, maple syrup in a small bowl and then add salt and pepper to taste.
Place all ingredients corn, red onion, avocado and tomatoes in a large serving bowl. Add dressing and toss well together.
Then sprinkle coriander leaves and mix again.
You can use other types of cherry tomatoes in this recipe. I would go for a variety of colour if possible.
This could easily be a meal in itself. Add a poached egg for a breakfast salad.