Smash burgers

Name: Smash burgers
Prep time: 10 min
Cook time: 15 min
Total time: 25 min
Cuisine: American
Ingredients: 4 burger buns sesame topped or brioche, whichever you prefer; 1 tbsp/15ml sunflower oil; 500g/1lb 2oz steak mince 15-20% fat is good; 4 slices mild cheddar or burger cheese; 1 red onion finely sliced; handfuls of iceberg lettuce finely shredded; 2 tomatoes sliced; 1 large gherkin sliced lengthways; mayonnaise ketchup and American mustard, or your preferred sauces, to serve