Wash the lettuce, cut into quarters, remove the hard stalk and cut the quarters into strips. Wash carrots, peel and cut or slice into fine strips and soak them for at least two hours. Drain corn kernels.
Wash spring onions, cut the white and the bright green parts into fine rings. Wash and halve cocktail tomatoes. Place everything into a salad bowl.
Froth up the lemon juice, balsamic vinegar, the oils and the mustard well with each other. Add seasoning. Cut the cress and mix 2/3 with the dressing. Spread the dressing over the salad and sprinkle the rest of the cress on top.