Combine olive oil, paprika, oregano, salt, and pepper in a glass bowl to create a marinade.
To commence preparing paella, incorporate the chicken and ensure it is thoroughly coated. Once coated, cover the mixture and place it in the refrigerator until it is required.
In a large skillet or paella pan, heat 2 tablespoons of olive oil over medium heat. Add the garlic and pepper flakes, and then mix in the rice. Continue to cook and stir until the rice is evenly coated with the oil, which should take approximately 3 minutes.
Include saffron strands, bay leaf, parsley, chicken broth, and lemon zest. Mix thoroughly and bring the mixture to a boiling point. Then, lower the heat to a medium-low setting, cover, and allow it to simmer for 20 minutes.
As the rice simmers, warm the olive oil in a different frying pan over medium heat. Incorporate the marinated chicken and cook for a duration of 3 minutes. Introduce the onion and continue cooking until it becomes translucent, typically around 5 minutes.
Begin by adding bell pepper and sausage to a pan. Cook and stir the mixture for approximately 5 minutes, ensuring to break up the sausage using a spatula. Next, introduce the shrimp into the pan and continue to cook and stir until the shrimp turn a vibrant pink color on the outside and the meat becomes opaque, which should take around 2 minutes.
Spread the mixture of rice onto a tray for serving, and then add the mixture of meat and seafood on top.