Slice the onion, cut the pepper into two pieces, and slice the courgette lengthwise into 4 pieces. Slice the beetroot and gherkin.
Heat a little oil in a griddle pan and fry the pepper, courgette, and onion until tender and lightly charred. Set aside.
Cut the halloumi into 1 cm slices. Fry in the same pan for 1–2 minutes per side, until golden and lightly charred.
In a separate pan, heat a little oil and fry the eggs to your liking. Alternatively, poach them in boiling water with a splash of vinegar.
Cut the burger buns in half and lightly toast them for extra flavour and structure.
Layer the courgette, pepper, and onion on the base of each bun. Add the grilled halloumi, followed by gherkin and beetroot slices. Top with a fried egg, then place the top bun on.
Serveimmediately while warm, with a side of fries or salad.