Prepare the beef base: In a large bowl, combine the beef mince with the salt, pepper, smoked paprika, and ground cumin. Mix gently with your hands until just combined—overworking the meat will make it tough. You should see the spices evenly flecked through the mince, giving it a warm, reddish hue.

Sear the patties: Heat the vegetable oil in a large non-stick skillet over medium-high heat until it shimmers. Divide the mince into 8 equal portions and place them in the hot pan, leaving space between each. Using a spatula, firmly press each portion into a thin, irregular patty—you'll hear a satisfying sizzle as the meat hits the pan. Cook for 3-4 minutes, until the edges turn a deep, crusty brown and the smell of seared beef fills your kitchen.

Flip and add aromatics: Flip each patty carefully—the undersides should be dark and caramelised with crispy edges. Sprinkle the diced onion and minced garlic around the patties, stirring them into the rendered fat. Cook for another 2-3 minutes, until the onions become translucent and release a sweet, fragrant aroma.

Create the sauce: Reduce the heat to medium-low. Add the tomato purée, ketchup, and Worcestershire sauce to the pan, stirring everything together. The sauce will bubble gently and turn a rich, glossy mahogany colour. Toss the smashed patties in the sauce until each piece is thoroughly coated—the mixture should be thick and cling to the meat.

Warm the tortillas: While the beef finishes cooking, warm your tortillas. You can do this in a dry pan over medium heat for 30 seconds per side, or wrap them in a damp tea towel and microwave for 30-45 seconds. They should become pliable and slightly toasted in spots, with a soft, steamy texture.

Assemble the tacos: Place a generous spoonful of the saucy smashed burger mixture down the centre of each tortilla. Top immediately with grated cheddar cheese so it begins to melt from the residual heat. Add shredded lettuce, diced tomatoes, a dollop of sour cream, and jalapeños if using. Serve straight away, while the patties are still hot and the cheese is oozing.