This is my favourite recipe for burgers, and they are vegetarian! Bonn appetite!
First, you need to clean your mushrooms. Big beefy large flat ones are the best, but you can use two or three mushrooms that are slightly smaller. But you'll need one big mushrooms per person. I have a mushroom brush, but if you don't have one then rinse them and scrub them a bit with some kitchen roll.
Next, mix a good glob of mayonnaise with some pesto - do it by eye and by taste until you've got enough to spread some on the top and bottom of all your burgers.
Now heat up a bit of oil in a big pan and put your mushrooms in. You'll need to turn them round a lot, or they'll burn.
This next step is optional, but it adds another layer of flavour to the burgers. Brush the mushrooms with some balsamic vinegar, sprinkle them with sugar, salt and pepper while they cook.
While you wait, get started on the halloumi (but keep turning your mushrooms). Halloumi is a salty, rubbery cheese made from sheep, goat and cow milk. It comes in roughly cuboid shaped blocks. If you can't get halloumi, paneer is an OK substitute. It won't be quite the same though, so use halloumi if you can.
Slice the halloumi so you have enough to divide equally between the burgers - you'll want the slices thickish.
If your mushrooms are cooked through, then you can take them out of the pan. Add enough oil to almost cover the bottom of the pan, and sprinkle the oil with paprika.
When the oil is hot enough, add your halloumi. Be careful not to splash your fingers! When it's brown and a bit crispy you can put it on a plate ready for assembly.
Next, wash the lettuce! Any kind is good, but curly lettuce works best. Now take some large tomatoes (probably only 1 or 2) and slice them up.
Now assemble however you wish!