Add the chicken thighs over some paper towels and pat dry, then season with salt on both sides, and then cut each chicken thigh into 1 1/2 inch (4 cm) pieces

Heat a 12-inch (30 cm) paella pan or cast iron skillet with a medium heat and add in the olive oil

After a couple of minutes, add in the pieces of chicken, all in a single layer, and fry for 3 minutes per side

Once the pieces of chicken are lightly browned, once again 3 minutes per side, make a well in the middle, add in the green beans, and mix with the olive oil

After 3 minutes and the green beans are lightly sautéed, make another well in the middle, add in the chopped garlic, and mix continuously

Once the garlic is lightly sautéed, about 1 minute, add in the paprika, and mix everything together until well mixed, then add in the grated tomatoes, and season with salt, mix together, and then simmer for a couple of minutes

After 3 to 4 minutes and the grated tomatoes have slightly thickened, add in the water, saffron, rosemary, and a pinch of salt, raise to a high heat and gently mix together

When it comes to a boil, add in the rice and the butter beans, and give it one final mix so everything is evenly distributed, after this step, do not mix the rice again, otherwise, it will start to release its starch and lose its texture

After simmering the rice for 10 minutes, lower the fire to a low-medium heat, and simmer for another 8 minutes or until all the liquid has been absorbed and the rice is just cooked through, then raise to a medium-high heat and go for 1 to 2 minutes, this is to achieve the socarrat, which is the bottom layer of crispy rice, then remove the pan from the heat

Cover the pan with a dishcloth and let it rest for 3 to 4 minutes, then uncover and serve, enjoy!