Place all dressing ingredients into Thermomix bowl and blend 10 sec/speed 8.
Remove from bowl and set aside.
Without washing, place water into Thermomix bowl and place chicken into simmering basket. Insert basket and cook 12 min/100ºC/speed 3.
Remove basket and drain Thermomix bowl. Return chicken to Thermomix bowl and shred 4 sec/Reverse/speed 4. Cool slightly.
To prepare the Banana blossom, peel off the hard outer layers and discard (or use as serving bowl). Cut in half lengthways and slice thinly. Soak in a large bowl of cold water with the lemon juice and salt for 10 minutes. Strain, keeping only the purple and white slices. Discard the rest.
Make salad by assembling banana blossom, baby spinach, cabbage, carrot, spring onions and Kaffir lime leaves onto each plate or large serving platter. Top with shredded chicken and dressing.
Serve with lime wedges and sliced chilli to taste.