Preheat the oven

• Preheat the oven to 400 °F (200 °C).

Slice the onions

• Thinly slice the onion and the red onion.

Make the batter

• In a bowl, combine the flour, olive oil and water.
• Add the salt, black pepper, garlic powder, paprika and cayenne pepper.
• Mix well until smooth and evenly colored.

Coat the onions

• Add the sliced onions to the batter and coat them generously.

Spread on the tray

• Drizzle a little olive oil onto parchment paper on a baking tray.
• Scoop out the onions with all the batter and spread them out evenly.
• Pack the mixture down firmly.

Top and bake

• Drizzle with a bit more olive oil and sprinkle over the grated Parmesan.
• Bake for 45 to 60 minutes, until the edges are nice and crispy.

Serve

• Cut into pieces and serve with ketchup.