Warm oil in a large stockpot over medium high heat and add onions and peppers. Cook for 3 minutes, or until vegetables soften.
Add in sofrito, shrimp tails, garlic, salt, cilantro, and thyme. Saute for another 3-4 minutes. Add in water and simmer water for about 10-15 minutes.
Turn off heat to allow shrimp broth to cool.
Asopao
Once the shrimp broth has cooled slightly, drain the pot in a colander over a VERY LARGE bowl or another pot to RESERVE THE SHRIMP BROTH.
In the same pot warm oil and we'll build the sofrito sauce by adding in chopped onions, chopped peppers, garlic and sofrito.
Allow this to cook for about a minute or until fragrant (stirring frequently to keep it from burning). Next, add in salt, pepper, oregano, sazon, and a pinch of cumin.
After twenty seconds, add in the tomato sauce and about a quarter cup of the raw shrimp and set the rest of the shrimp to the side until the end. Allow the sofrito sauce to infuse with the shrimp for about thirty seconds before gently adding in the shrimp broth.
Higher heat and bring shrimp broth to a boil; add in rice. Lower heat to medium or until the shrimp broth is at a steady and gentle simmer.
Allow the rice to cook, stirring it occasionally.
Once rice is tender and cooked through, add in the remaining raw shrimp and chopped cilantro. Cook an additional five minutes, or until shrimp is pink and cooked through.
Taste for seasoning.
Notes
If you want the asopao thinner, you can add more water. Asopao will thicken as it cools.