Cook tortellini in large pot of boiling salted water until barely tender, stirr ing occasionally to prevent sticking. Drain thoroughly. Meanwhile, bring cream to boil in heavy large saucepan. Reduce heat. Add nutmeg and simmer until sli ghtly thickened, about 8 minutes. Return tortellini to pot. Add warm cream, Pa rmesan, peas and prosciutto. Simmer over low heat until tortellini are tender and sauce thickens, stirring occasionally, about 4 minutes. Season with salt an d pepper. Divide among four warm bowls and serve.