In a medium saucepan cook and stir the zucchini, onion, carrot, rosemary, and black pepper in hot oil just until vegetables are tender. Stir in barley.
Meanwhile, in a small saucepan bring Vegetable Stock to boiling. Reduce heat and simmer. Slowly add 1 cup of the stock to barley mixture, stirring constantly. Continue to cook and stir over medium heat until liquid is absorbed. Add the remaining stock, about 1/2 cup at a time, stirring constantly until liquid is absorbed. (This should take 10 to 15 minutes total.)
Stir in the evaporated milk. Cook and stir for 2 minutes more. Season to taste with salt and additional black pepper.