Cut the Roma tomato into small cubes.

Finely grate the cheese.

Heat the oil in a pan over medium-low heat. Once hot, add the Arborio rice and toast it, stirring frequently, until it turns lightly golden. Meanwhile, warm the water in the microwave.

Add the frozen peas, 1 cup of water, salt, parsley flakes, and pepper to the rice. Stir constantly until the water evaporates.

Add another cup of water and continue stirring until it evaporates. Repeat this step with one more cup of water.

Finally, add ½ cup of water. Stir constantly until the water evaporates. Taste the rice—if it's not tender and creamy, add another ½ cup of water and continue cooking while stirring constantly. Adjust the salt and pepper if needed.

Remove the pan from heat and add the diced Roma tomato, stirring a few times to combine. Add the grated cheese and stir until it melts.