Heat olive oil in a large pan over medium heat.
Add chopped onion and minced garlic, sauté until soft.
Stir in diced tomatoes, green beans, and red bell pepper. Cook for a few minutes.
Add paella rice, vegetable broth, smoked paprika, and saffron threads. Stir well.
Bring to a boil, then reduce heat and simmer for about 20 minutes, or until rice is cooked.
Stir in frozen peas and cook for another 5 minutes.
Serve hot with lemon wedges on the side.