Start with making the pickled cucumber a couple of hours before serving the burgers – or days ahead.
Cut the cucumber into thin slices and place them in a jar or a bowl.
In a pot, combine all of the other ingredients and bring to a boil. As soon as all of the salt and sugar are dissolved, remove from heat and add it to the jar of cucumber. The cucumber should more or less be covered. Put on a lit and place in the fridge. As soon as you start using the pickled cucumbers, your can add new slices of cucumber to the jar and reuse the vinegar mix.
Yoghurt Aioli with garlic
Peel and crush the garlic. Mix it with mayo and fromage frais. Season with salt and pepper.
Portobello burgers
Preheat oven to 400 °F/200 °C.
Mix oil, with crushed garlic, chopped rosemary, salt and pepper. Rub the dressing into the portobello mushrooms and on the green bean (if you use fresh beans, boil them for 5 minutes before going into the oven). Place everything on a baking shed and bake in oven for about 15-20 min, or until the portobello is tender and the beans are crispy.
While the beans and Portobello are in the oven you prepare the rest. Shape the meat into hamburgers. Season with salt and pepper and fry on a pan until done and juicy.
Toast the bread and add a Tbsp of aioli. Add spinach, beef, avocado slices, ketchup, picked cucumber and at last the baked Portobello mushroom.
Notes
Serve the burgers with bean fries and lots of aioli on the side. Enjoy!