Heat oil in a medium saucepan over medium heat until it slides easily across pan bottom. Add onion and cook, stirring occasionally, until soft, about 15 minutes. Add rice, salt, and pepper and cook, stirring, until rice is heated through and slightly translucent, about 1 minute.
Add enough stock to almost cover rice, about 2 cups. Simmer, stirring frequently, until rice has absorbed stock, 5 to 10 minutes. Stir in tomatoes, garlic, and another cup of stock. Cook, stirring, until rice looks dry, then add another cup of stock. Continue gradually adding stock, cooking, and stirring, until rice is tender and creamy, about 25 minutes. Stir in butter and cheese, season with salt and pepper, and serve.
White Chicken Stock:
Rinse chicken bones or chicken parts well. Remove the fat and skin if any, and place into a pot with just enough hot water to cover. Bring to a boil over medium-high heat and let boil for about 2 minutes. Drain the chicken and discard the water (this will not remove flavor, just the blood and much of the coagulated proteins that cause scum). Return the chicken to the pot, cover with fresh water and bring to a simmer over medium-high heat. Reduce the heat to medium and gently simmer stock for about 1 hour, skimming whenever fat or scum accumulates on the surface. Add more hot water, if necessary, to keep the level consistent.
After 1 hour simmering, add onion, carrot, celery, leeks, bay leaf, and peppercorns. Simmer for 15 minutes. Add parsley and thyme and simmer for an additional 15 minutes. Take pot off heat and strain stock. Cool, and refrigerate for up to 5 days or freeze for up to 4 months.
Yield: approximately 12 cups stock
Roasted Tomatoes and Garlic:
Preheat oven to 350 degrees F. Cut tomatoes in half cross-wise (through the equator), then place tomatoes, garlic cloves, and olive oil in a large bowl. Season with salt and pepper and mix gently. Line 2 large, rimmed baking sheets with parchment paper or aluminum foil. Place tomato halves on baking sheets, cut side down, and pour any olive oil left in bowl over them. Divide garlic and thyme evenly between baking sheets. Bake until tomato skins loosen, about 20 minutes.
Remove and discard tomato skins. Pour any juices that have accumulated into a bowl and reserve. Return tomatoes to oven and reduce temperature to 275 degrees. Continue roasting, periodically pouring off and reserving juices, until tomatoes are slightly shrunken and appear cooked and concentrated but not yet dry, 3 or 4 hours more.
Remove tomatoes from oven and allow them to cool on baking sheets. Discard thyme. Transfer tomatoes and garlic to separate containers. Store tomatoes, garlic cloves, and reserved tomato juices in refrigerator for up to 1 week, or in the freezer for up to 6 months.
Yield: 40 roasted tomato halves, approximately 20 roasted garlic cloves, and 1 to 3 cups roasted tomato juice
Colicchio: "A white chicken stock is the first step toward making brown chicken stock; it also has many uses of its own."
"Roasting intensifies the flavor of even less-than-spectacular tomatoes, in case local greenmarket varieties are unavailable...The leftover roasted garlic, incidentally, has a creamy, mellow flavor not found in the raw vegetable and makes a great spread on a piece of crusty bread."