Put the vegetable stock in a pitcher and whisk in the mustard, celery salt, pepper, basil and oregano. Set aside.
Heat 1 tablespoon of the olive oil over medium heat in a large casserole or saucepan with a lid.(I use my Le Creuset casserole dish.)
Gently sauté the onion until it begins to soften.
Stir in the garlic, followed by the the pearl barley and let cook for a moment or two, stirring constantly.
Pour in the stock mixture all at once and turn the heat up a little to bring the mixture to a boil, stirring constantly.
Turn back the heat to low, pop on a lid and let the orzotto cook for about 40 minutes, stirring every seven or eight minutes, being careful the mixutre does not stick to the bottom of the pan.
Once the orzotto has been cooking for about 20 minutes, heat the remaining tablespoon of oil in a frying pan over medium heat.
Stir in the mushrooms and zucchini and cook until they begin to soften and take up some colour.
(Don't forget to keep stirring the orzotto occasionally.
Finally, stir in the asparagus and/or peas and stir fry until nearly tender crisp.
Add the vegetables to the orzotto and let the mixture continue to cook until all the liquid has been absorbed.
Taste the orzotto and if the barley is not tender enough, you can stir in a little more stock, boiling water or Madeira.
Once the orzotto is tender, taste for seasoning. You can add a bit of salt and/or pepper if needed.
Divide between 4 bowls or plates.
Garnish with the flat leaf parsley.
Serve with a crisp green salad, a tomato and onion salad, or hot rolls if you like.