Preheat the oven to 400°F and keep a ceramic or metal baking pan ready.
In a saucepan, bring the ground tomato mixture to a boil on medium-high heat. Lower the heat and simmer for 12~15 minutes or until the mixture is thickened and the flavors are intense.
Heat oil in a saute pan, add onion and cook till they are lightly browned around the edges, about 4~5 minutes.
Add the tomato paste and cook, stirring frequently, for 2~3 minutes.
Now add the add rice and cook till the grains appear lightly toasted. Remove from the heat and spread the fried rice in the baking pan.
Pour the simmered tomato mixture along with boiling water over the rice and then stir in the peas. Cover with an aluminum foil and bake for 25 minutes.
Peel back the foil, stir twice, seal the foil again, and then turn the pan 180°F; this will help redistribute the heat over more even baking.
Bake another 30 minutes, then remove from oven and remove the foil.
The grains should have absorbed the liquid and the rice should be firm, chewy, but not hard in the center.
When done, remove from the oven and let stand covered for 5 minutes. Granish with chopped cilantro and serve hot.