Put your oven on pre-heat of 200 C while you prepare other stuff. Put a roasting tin inside it. In a saucepan of boiling water, blanch the beans for two minutes or until tender. Scoop them out with a spoon into a colander and let them cool down under running water. In the same pan with water, boil the potatoes for five minutes or until you believe they have gone tender. Drain the water out.
Put the potatoes in a large bowl and add the the oil, paprika, salt flakes and crushed peppercorns to them. Mix well so that the potatoes are coated well. Tip these wedges into the roasting tin and roast in the oven for 15 minutes. Sprinkle them for 30 minutes and continue toasting for another half an hour, changing sides so that they are equally toasted.
Remove the potatoes and set them aside for latter use. Have them covered to keep them warm. Combine the beans, lettuce, onion, cucumber and tomatoes in a large bowl. Toss together well and add the lemon juice and salt and freshly ground pepper. Mix well.
Make the dressing now. Combine the brie and milk in a saucepan and heat slowly until they merge together and form a well blended solution. To the mixture add the tarragon and pepper. Stir well to combine.
Divide the bean tomato vegetable salad into four separate bowls. Add the roasted potato wedges to them and then season with the hot brie dressing. Serve immediately.