Preheat the oven to 400 º F.

In a saucepan, combine the broth and saffron over medium-high heat, bring to a boil, then reduce the heat to low and cover while you assemble the paella.

Set a box grater over a bowl and run the cut side of the tomatoes across the coarse side of the grater, continuing until you are left with just the skin.

Heat a 17-to 18-inch paella pan over two or three burners or heat two 10-to 11-inch cast-iron skillets over medium-high heat. Pour in the olive oil and when it shimmers, add the shishitos, searing each side for a minute or two, then use tongs to transfer them to a plate.

Stir in the onion, garlic, and bell peppers and cook, stirring frequently, until the vegetables are soft, 6 to 8 minutes. Stir in the paprika, cumin, and salt and cook until fragrant, about 30 seconds. Stir in the green beans and cook, stirring frequently, until they lose a little of their crunch.

Stir in the tomato pulp and parsley and cook for about 30 seconds, then stir in the rice, coating it well with the pan mixture. Stir in the broth, chickpeas, and spinach, taste, and add more salt if needed. Cook, stirring and rotating the pan occasionally, until the mixture is no longer soupy, but the rice is still covered by liquid, about 5 minutes.

Nestle the shishitos on the rice and transfer the pan to the oven. Bake, uncovered, until the rice is al dente, 12 to 15 minutes. Remove, cover with aluminum foil, and let it sit for 10 minutes, until the rice is fully cooked.

Serve hot, with the aioli on the side.