Roughly chop the spring onions, carrot and celery into 3 cm pieces and add to your Thermomix bowl. Roughly chop the red capsicum into strips and also add it to the bowl. Mix for 3 seconds, speed 6 to chop. Transfer the ingredients to a separate bowl until needed.
Rinse out your Thermomix bowl and add 1000 grams of water. Cook for 10 minutes, 100 degrees, speed 2.
Add the dried macaroni pasta and the salt and cook for 8 minutes, 100 degrees, speed 1 reverse.
Drain the cooked pasta and set it aside to cool.
In a clean and dry Thermomix bowl, add the dressing ingredients and mix for 6 seconds, speed 4. Scrape down the sides of your Thermomix bowl and mix for a further 5 seconds, speed 3.
Place the cooled pasta into a large serving bowl and add the diced/grated vegetables plus the dressing. Gently fold with a large spoon to combine all of the ingredients.
Cover the bowl with cling wrap (or a beeswax wrap) and place the pasta salad into the fridge for 2 hours to chill.