Heat a large paella pan (or wide, shallow pan) over medium-high heat. Add olive oil.
Season and brown the chicken and rabbit pieces all over. Push to the sides of the pan.
Add the green beans and cook for 3 minutes. Add the onion, garlic and grated tomato. Cook, stirring, for 5 minutes until the sofrito is thick and jammy.
Stir in the smoked paprika. Add the rice and stir to coat in the sofrito for 2 minutes.
Pour in the hot stock and saffron water. Stir once to distribute the ingredients evenly. Do not stir again.
Cook over medium heat for 10 minutes, then reduce to low and cook for a further 8–10 minutes until the rice has absorbed all the stock. Listen for a gentle crackling — this is the prized socarrat (crispy rice base) forming.
Remove from heat and rest for 5 minutes covered with foil. Serve directly from the pan with lemon wedges.