Italian-Style Frittata Burger

Ingredients:

Hamburgers

• 4 ciabatta or sesame seed buns, halved, toasted if desired
• 700 g of ground beef shoulder
• 1.5 tbsp. l. canola oil
• 1 handful of arugula leaves

Ketchup "Fra Diablo"

• 1 tbsp. l. olive oil
• 3 cloves garlic, minced
• 1/4 teaspoon red chili flakes
• 3/4 cup tomato sauce
• 2 teaspoons chopped oregano leaves
• 2 tsp red wine vinegar
• 2 tablespoons chopped basil leaves

Cheese frittata

• 1 cup grated fontina, parmesan, asiago, or a mixture of any of these cheeses
• 2 teaspoons flour

Preparation:

1. To prepare ketchupHeat the oil in a small, nonreactive saucepan over medium heat. Add the garlic and chili flakes and cook for 1 minute. Add the tomato and oregano sauce and cook for 2 minutes. Remove from heat, stir in the basil vinegar, and season with salt and pepper. Strain through a sieve and pour into a bowl. Cool to room temperature or cover and refrigerate for up to 1 day. To serve, transfer to a gravy boat and let sit at room temperature.
2. To make frittata fricoIn a bowl, combine the cheese and flour. Heat a 20cm nonstick skillet over medium-high heat. Add 3 tablespoons of the cheese mixture and cook until the bottom is golden brown.
   
   Flip with a heat-resistant silicone spatula and cook for another 10-15 seconds. Transfer to a plate to cool. Wipe the pan with a paper towel and repeat with the remaining tortillas.
3. Divide the meat into 4 equal portions, each weighing approximately 170 grams. Form each portion into a patty approximately 2 cm thick, and make a wide indentation in the center with your thumb. Season both sides with salt and pepper. Cook the patties using oil.
4. Assemble the burger with the patty and cheese patty and serve with ketchup.
   
   Recipe Burger with mushrooms and homemade ketchup.