BOIL the potatoes, pumpkin, corn and peas until tender, drain and then mash. Stir in the cheese, VEGEMITE and cornflake crumbs. Cool slightly.
PLACE the flour, egg and extra cornflake crumbs in separate shallow dishes. Shape the vegetable mixture into 12 croquettes. Lightly coat in flour, then egg and finally crumbs. Refrigerate until firm.
HEAT the oil in a frypan and cook the croquettes for 1-2 minutes on each side, until golden and heated through. Drain briefly on paper towel before serving with tomato sauce. Serve immediately.