Peel and finely slice the shallots. Cook the shallots in a good splash of olive oil and sauté very gently for 8 minutes until totally softened but not coloured. Season with salt to taste.
After 5 minutes of cooking the shallots, drop the broccoli in boiling water & cook for 2 minutes.
While the shallots and broccoli cook fry the croutons in some olive oil until golden brown, 4 minutes or so.
Combine the sugar, mustard, anchovies and vinegar in a cup or small bowl and then beat in the olive oil until the dressing is emulsified and creamy. Toss the cooked shallots and broccoli in a serving bowl with the radishes.
Strip the tarragon from the stalks and scatter it on top of the salad followed by the walnut pieces, chives and croutons. Eat warm.