In a saucepan, add chicken stock and tomato sauce and bring to a fast simmer.
In a separate 10-inch skillet, heat the vegetable oil over medium high heat until shimmering. Add rice, and sauté until golden brown.
Toss in TexMex spice blend. Add vegetables, and sauté until soft.
Carefully add the hot liquid (will bubble fiercely at first). Give it a good stir, cover, reduce heat to fast simmer, set timer for 15 minutes.
Don’t remove cover or peek until time is up. Once time is up, remove from heat, stir in cilantro, fluff rice, then let stand for 5 minutes before serving hot.