In a heavy-bottomed medium saucepan, heat the olive oil. Add the onion and saute until fragrant and translucent. Add the orzo or barley and toast for 2 minutes, stirring occasionally. Add the wine and cook until absorbed.
Gradually add the stock, stirring frequently. Bring to a simmer and cover; cook for 8 to 10 minutes until the liquid is almost absorbed and orzo or barley is tender. Remove from heat.
Stir in the vegetables, grated cheese, fresh herbs or aromatics, heavy cream, and vinegar. Season the orzotto with salt and pepper and serve.
Lemon-Asparagus Orzotto: add 1/2 cup steamed diced fresh asparagus, 1 tablespoon lemon juice, and zest from 1/2 lemon.
Mushroom-Orzotto: 1 cup wild or culitvated mushrooms. Substitute chicken or beef stock with mushroom stock. Add 3/4 teaspoon fresh chopped thyme leaves and 1/2 cup Parmesan cheese.
Sweet Corn with Bacon Orzotto: Add 1/2 cup sweet corn, 1 tablespoon sugar, and 1/2 cup cooked and crumbled bacon.