Finely chop the onion and heat the butter in a large pot, add the chopped onion and let it brown for a few minutes. Add the peas and cook for about 15 minutes, until they become tender, if necessary adding the vegetable broth and salt. Transfer the cooked peas in a blender and blend to obtain a velvety cream. Put the cream of peas in the pan and add the soft cheese and pepper, mix well and keep warm. Meanwhile, boil salted water and let cook the orecchiette. Drain “al dente” and make them jump quickly into the saucepan with the cream. Serve hot the orecchiette with peas cream with a generous sprinkling of grated Parmesan cheese.