Heat the oil in a stock pot over medium heat.
Add the rice and stir constantly for 3 minutes, until lightly toasted.
Add the carrot and onion. Cook for 2 minutes, stirring occasionally.
Add the garlic, cumin, salt, tomato sauce, and chicken broth.
Stir to combine.
Slice the jalapeño lengthwise and add it to the pot, if using.
Cover and cook over medium-low heat for 10 minutes.
Do NOT stir the rice.
Add the shrimp and ¼ cup water.
Cover and cook for 2 minutes.
Turn off the heat and leave the pot covered for 5 minutes.
Uncover and check the rice.
It should be tender and fluffy, and the shrimp should be cooked through.
If the rice is not fully cooked, add a splash of water, cover, and let it sit for 5 more minutes with the heat off.
Once the rice is cooked, gently stir to combine.
Serve immediately.