Heat a medium nonstick skillet over medium-high heat. Add the EVOO (1 turn of the pan) and the chorizo. Cook 1 to 2 minutes, then add the onion and cook for another 3 to 4 minutes. Add the black beans and the pimientos and heat through, another 1 to 2 minutes.
In a large saucepan, bring the chicken stock and butter to a boil and stir in the pumpkin. Return to a boil, whisk in the polenta and stir until it masses together, 2 minutes. (Watch out for splatters.) Remove the polenta from the heat and add the thyme, salt, pepper and cheese. Adjust the seasonings. Pile the polenta on plates and top with the chorizo and beans. Garnish with the chopped parsley and serve.