In a small pot, combine packet of chicken bouillon with three cups water and bring to a boil. Once boiling, reduce heat and keep at a simmer.
Meanwhile, in a medium saucepan, heat olive oil and butter; add onion and garlic. Cook until soft without coloring. Add chorizo, and cook for 2 minutes. Then add rice. Cook for a further 2 minutes, ensuring all the rice is coated.
Add white wine, and continue to stir until wine has been absorbed. Then add one ladle of hot bouillon. Reduce heat to a simmer. Keep stirring, allowing each ladle of bouillon to be absorbed before adding the next.
Once all of the bouillon has been used, stir in the peas, pimientos and Parmesan. Remove from heat and cover with a lid for 2 minutes. Serve while hot.