Heat 2 large, deep frying pans over a medium heat. When hot, divide the chorizo between the pans and cook, stirring occasionally, for 3-4 minutes, until turning golden and the oil has been released. Remove with a slotted spoon and set aside.
Divide the chicken between the pans and cook for 3-4 minutes, stirring, until golden. Remove with a slotted spoon and set aside.
Add 1 tablespoon olive oil to each pan, then divide the onions between them. Cook, stirring occasionally, for 6-8 minutes, until softened. Divide the garlic and paprika between each pan and cook for 1 minute. Divide the rice between them, stir to coat in the oil. Add 1 litre hot stock to each. Simmer for 10 minutes, stirring occasionally.
Return the chicken to the pans and divide the peppers, beans and tomatoes between the pans. Stir and cook for 5 minutes, adding a little more stock or hot water if necessary. Season and stir the chorizo and parsley into each pan. Divide 1 pan of the paella between 2 freezer-proof boxes, cool, label and freeze (see freezing tip).
Continue to cook the other paella for 5 minutes or until the rice is just tender and most of the liquid has evaporated. Serve with lemon wedges to squeeze over.