Heat olive oil in a large skillet or paella pan over medium heat.
Add the chopped onion and cook until translucent, about 5 minutes.
Add the minced garlic and cook for another minute.
Add the chopped bell peppers and green beans. Cook for about 5 minutes, stirring occasionally.
Stir in the rice, coating it well with the oil and vegetables.
Pour in the vegetable broth, smoked paprika, and saffron (with its soaking water). Stir to combine.
Bring to a boil, then reduce heat to low. Simmer uncovered for about 20 minutes, or until the rice is tender and has absorbed the liquid.
Add the peas during the last 5 minutes of cooking.
Remove from heat and let the paella rest for 5 minutes before serving.
Serve with lemon wedges on the side.