1. Heat olive oil in a paella pan over medium heat.
2. Add chopped onion and minced garlic, sauté until translucent.
3. Stir in diced tomatoes and cook for 5 minutes.
4. Add paella rice and stir to coat with the tomato mixture.
5. Pour in chicken broth and add saffron threads, bring to a boil.
6. Reduce heat to low and simmer for 15 minutes, without stirring.
7. Arrange mixed seafood on top of the rice, cover, and cook for another 10 minutes.
8. Add green peas, paprika, salt, and black pepper, cook for 5 more minutes.
9. Remove from heat and let it rest for 5 minutes before serving.
10. Serve with lemon wedges.