Roast the tomato in the oven at 400F for 10-15 minutes
Add a dollop of oil to a saucepan on medium-high heat
Add the rice and stir frequently until opaque and golden brown
Add the roasted tomato to a blender along with the 1/2 onion and garlic clove
Pulse blend. Add a couple tablespoons of stock if it won't blend at first
Add the tomato puree to the rice and saute for a few minutes
Add the stock and 1/2 teaspoon salt
Stir well
Bring to a light boil, then simmer on medium-low heat until most of the liquid is absorbed
Turn off heat, cover, and let sit in its own steam for 5-10 minutes
Salt to taste