Vegetable savoury mince

Ingredients (4 servings): 1 tablespoon olive oil 1 large zucchini (baby marrow), quartered lengthways 2 corn cobs, trimmed or (1 cup of frozen corn kernels) 1 large brown onion, chopped 2 garlic cloves, crushed 500g lean beef mince 4 medium tomatoes, chopped 1 tablespoon tomato paste 1 cup beef liquid stock 1 tablespoon Worcestershire sauce…