Place pecans on an ungreased baking tray. Bake at 180 degrees C for 5 to 8 minutes.
Melt butter in a large, heavy frypan over low heat; add onion, and saute until very tender, about 15 minutes. Stir in pumpkin and cover. Continue cooking, stirring occasionally, until pumpkin is tender but still holds its shape about 15 minutes. Season with salt and pepper.
Stir in half the pecans and half the parsley. Transfer mixture to a serving bowl. Sprinkle with remaining pecans and parsley to serve.