Bring a steamer pot of hot tap water to a boil. Bring a small pot of hot tap water to a boil.
Cook eggs
Cook 4 eggs in the small pot of boiling water for 8 minutes or until cooked to your liking. Drain and run under cold water to cool before peeling and slicing in half.
Make patties
Grate 50 g cheese. Drain and rinse 400 g brown lentils. Grate 6 gherkins and add to a large bowl with cheese, lentils, 400 g beef mince and a grind of pepper and mix until combined. Divide the beef mixture into 4 equal-size patties.
Cook patties
Heat 1 tbsp olive oil in a large frypan on a medium-high heat. Cook the patties for 1 minute on each side and then brush them with 2 tbsps Dijon mustard. Cook for 3 minutes on each side, or until golden and cooked through. Halve 4 burger buns and sit the burger patties inside, then slice each burger in half and re-toast the cut sides for a final 30 seconds, or until golden and cooked through.
Make dressing
In a large bowl whisk to combine 1 tbsp balsamic vinegar, 1 tbsp apple cider vinegar, 1 tbsp olive oil and ½ tsp Dijon mustard. Season with salt and pepper.
Make salad
Tear the leaves of ½ lettuce. Slice 200 g cherry tomatoes in half. Thinly slice 1 cucumber. Peel and julienne or grate 1 carrot. Add the lettuce, tomatoes, cucumber and carrot to the bowl with the dressing. Season with salt and pepper and toss to combine.
To serve
Divide the beef and lentil burgers between plates. Serve with the garden salad topped with eggs on the side.