Put a teaspoon of olive oil, the chopped vegetables, herbs and garlic in a large pan with a close fitting lid and stir-fry them for a minute or two only. Add the wine, ½ tsp. salt and plenty of freshly milled black pepper. Place the pan on a very high heat. As soon as the liquid is boiling, add the mussels and put the lid on the pan, ensuring a good tight fit. Steam the mussels for just long enough so that all the mussels are open, but no longer than that, or the mussels will be less tender. Serve immediately in a warmed serving dish. The crusty bread is delicious if dipped in the broth in the pan.