1. Prepare the Mushrooms

• Preheat your oven to 375°F (190°C).
• Wipe the Portobello mushroom caps with a damp cloth to remove dirt.
• Remove the stems and scrape out the gills with a spoon to create a flat surface for the toppings.

2. Make the Sauce

• Spray a small saucepan with cooking oil and heat over medium heat.
• Add the finely chopped onion and minced garlic. Sauté for 2-3 minutes, or until fragrant and the onion turns translucent.
• Stir in the passata, chicken or vegetable stock, and tomato paste. Add a pinch of oregano and Italian parsley.
• Simmer for about 10 minutes, allowing the sauce to thicken slightly.

3. Prepare the Toppings

• While the sauce simmers, slice the smoked chicken sausage and chop the red onion.

4. Assemble the Pizza Caps

• Place the prepared mushroom caps on a baking sheet lined with parchment paper.
• Spread a layer of the tomato sauce inside each mushroom cap.
• Sprinkle shredded mozzarella cheese on top of the sauce.
• Add your desired toppings, such as sliced chicken sausage, black olives, or chopped red onion.

5. Bake the Pizza Caps

• Bake in the preheated oven for 15-20 minutes, or until the cheese is melted and bubbly, and the mushrooms are tender.

6. Serve

• Remove the Portobello pizza caps from the oven and let them cool slightly.
• Garnish with additional parsley if desired and serve warm.