Summer Squash Stir-fry

• 2 tablespoons olive oil
• 2 medium zucchini, sliced
• 2 medium yellow squash, sliced
• 1 medium onion, chopped
• 1 clove garlic, crushed
• 1 large ripe tomato, peeled and chopped
• 1 tablespoon chopped fresh parsley
• 1 tablespoon Worcestershire sauce
• 2 tablespoons tomato paste
• 1 teaspoon salt