Heat the butter and oil in a heavy wide saucepan. When foaming subsides add the onion and cook for 5 minutes or until golden brown. Add half of the celery and carrot and cook for 3 to 4 minutes or until tender but still crisp. Add the rice and cook, stirring continuously, for 5 minutes or until toasty. Add the garlic and simmer a few seconds. Add 1/2 cup boiling water and cook until rice has fully absorbed it. Continue this way until 1 1/2 cups water have been absorbed, then add 1 cup of boiling water.
After 20 minutes or when the rice is half cooked add the remaining celery and carrot and cook for 10 minutes more. Add the peas and finish cooking the rice. Season to taste with salt and pepper. Right before serving, stir in the Parmesan cheese and basil. Garnish with pine nuts.
(If you want a more ample meal, serve this with grilled boneless chicken breasts marinated in lemon juice; grill them when rice is half way done.)