How to Make It
Using a sharp knife, trim the artichoke stems to 1 inch and cut off 1 inch from the tops. Using kitchen scissors, trim 1/2 inch from the outer leaves. Cut the artichokes in half and scoop out the spiky leaves and hairy chokes. Steam the artichokes, cut side down, over boiling water until just tender, 10 to 12 minutes. Transfer to a plate and let cool, then pat dry with paper towels.
Light a grill, heat a grill pan or preheat the broiler. In a small bowl, combine 1/2 cup of the oil with the herbes de Provence and brush it on the artichokes, fennel, tomato, zucchini and Portobellos. Sprinkle the vegetables with salt and pepper and grill or broil, turning, until tender and lightly charred, about 2 minutes for the tomato, about 8 minutes for the artichokes, about 16 minutes for the fennel and about 25 minutes for the zucchini and mushrooms. Transfer the vegetables to a platter, cover with foil and keep warm.
In a bowl, combine the vinegar with the mustard and Worcestershire sauce. Whisk in the remaining 1/4 cup of olive oil and season with salt and pepper. Drizzle the vegetables with the dressing and serve warm or at room temperature.