Cover the French fries in water. Let soak for 10 - 15 minutes. Then drain well.
Preheat the oven to 400°F (200°C).
Place the bratwurst on a baking sheet and cook in the oven, flipping once about halfway through, to an internal temperature of 155°F (68°C) using a thermometer.
Make the Curry Ketchup: While the sausages are cooking, in a saucepan, heat a the vegetable oil over medium heat. Add the onion and sauté until translucent, about 3 minutes. Stir in the garlic and cook for another 1 minute until fragrant. Add the curry powder, paprika, cayenne pepper, salt, and black pepper to the onion and garlic mixture. Cook for an additional 2 minutes, stirring constantly to toast the spices. Pour in the tomato ketchup and water into the saucepan. Stir well to combine all the ingredients. Allow the sauce to simmer over low heat for about 5-7 minutes, stirring occasionally.
Preheat the air fryer to 400°F (200°C).
In a bowl, toss the potato with Extra virgin olive oil, garlic powder, salt, and pepper, ensuring they are evenly coated.
Place the seasoned potatoes in the air fryer basket and cook at 400°F (200°C) for about 15 minutes, shaking or flipping them, then cook for 5 minutes more until the fries are crispy and golden.
Slice the Bratwurst: Once the bratwurst sausages are cooked through, remove them from the oven and let rest for 3 to 5 minutes. Slice them into bite-sized pieces.
Mix all the ingredients for the lemonade. Serve over ice.
Pour the curry ketchup sauce over the sliced bratwurst. Serve with a side of french fries and homemade lemonade.