I ate food served out of small vans twice in 24 hours this weekend and the two experiences could not have exemplified better what I love and hate about London. First, a hipster pop-up restaurant in Southwark, a one night only conceptual dining experience, learned about through word-of-mouth and ticketed online and second, a street food stall in Brixton market with some plastic tables and chairs set up opposite the recreation centre. Which do you suppose I loved and which made me seethingly homicidal? Hmm…

I’m usually pretty positive on this blog, mostly because I’m not a reviewer and I write about the places I’ve already chosen to go, so chances are I’m going to like them. But this, dear readers, is going to be a bit of a rant. My good friend T had suggested we go to a pop-up restaurant event called Acute Bliss in the Urban Physic Garden in Southwark. The garden is a summer project by a collective of gardeners and various collaborators to create a medicinal garden in a neglected part of London. They are running all kinds of events, from talks on medicine to theatre and art classes. I imagined the restaurant run out of a converted ambulance would feature dishes cooked with medicinal herbs and that the entertainment might include learning about the garden. I was so very wrong.

Things started to go south when we arrived a little early, hoping to walk in the garden. Everything was closed and bolted and when we found someone to ask, he told us to come back at 7:30, although the ticket said 7:15. ‘It’s all part of the experience,’ he said. ‘No, you’re just running late,’ we replied. BS-ing guests before they’re even in the door is not really a great start, but we went off for a drink as instructed. When we returned, a crowd had formed and people were being admitted in groups of six. A rather excitable hipster seemed to think this formed a pleasingly exclusive ambience. We felt like we were being made to wait yet longer. When we finally got inside, we were immediately told photography was forbidden. The most upscale restaurants happily let patrons photograph their meal, but I guess these people are even more exclusive. We were then sent to see a ‘nurse’ who was rude to us in a clichéd Mean Head Nurse way and gave us a drink whose ingredients she refused to divulge. As we were sent to different ‘rooms’ we were given canapés (like a bacon-wrapped date) with fantasy names (dragon’s blood etc). I felt like I was being a Bad Sport but I kinda like to know what I’m eating and the Harry Potter nomenclature struck me as silly rather than cool.

After rather too much of this trying-too-hard wackiness, we were seated at a communal table. The ‘doctor’ and ‘nurse’ forced us all to join in a song about how fun it all was which you probably don’t need me to tell you was excruciating. It was at this point that I realised that I was stuck in a party full of posh people for whom this was all a jolly wheeze. They probably thought it was like nanny mixed with midnight feasts in the dorm mixed with the Footlights. I know I’m dragging out my class bias here but seriously, I felt like I’d inadvertently crashed an upper class kids’ party that was unaccountably full of besuited grown-ups.

When the food eventually came, we realised that a) those little canapés had been the starter and b) the main course was about the size of a small lunch. A tiny portion of braised pork with apples came with a hunk of not-so-fresh baguette and some salad. The pork was nice enough, you’d have been happy if a friend who wasn’t a big cook served it, but for £35? It was worth maybe £6 or £7 at a lunch stand but it was by no means restaurant-quality food. They couldn’t even be bothered to cook us some rice or potatoes! As Woody Allen said, the food was terrible and such small portions. Meanwhile, vegetarian T was not served until everyone else was almost finished and her food was a mound of fridge-cold lentils topped with a ratty-looking runny egg. She looked like she was about to burst into tears and I really couldn’t blame her.

The final horror came when, after our ‘main course’, grumpy and crucially still hungry, we were herded over to a stage area where the ‘doctor’ and ‘nurse’ acted out a sub-panto piece of theatre about their worldwide hunt for exotic ingredients. Honestly, words fail me about how bad this part was. I’m not sure if it was meant to be tongue-in-cheek or what, but it was just leaden and endless and grim. On the way back the ‘doctor’ kept touching me in a way I did not appreciate. We ditched our desserts – a chocolate cake so alcoholic that it came with afterburn – and quietly fled, leaving the poshoes happily bunched around a campfire in the warm glow of their unique experience. Meanwhile, we went looking for a chip shop…

The next morning, hungover and ravenous, we went to Brixton market to cleanse our minds of the hipster nightmare. The ambience was everything the pop-up restaurant was not: friendly, diverse, lively, with the kind of buzz a real city produces of many languages, cultures and activities rubbing against each other, sparking and fizzing. I pity the people who are scared of ‘multiculturalism’, I really do. Why anyone would prefer an ersatz fantasy of exotic mythology to a proper urban neighbourhood is a mystery to me. Granted, the gentrified cafes in Brixton Village are a bit of a primer on Stuff White People Like, but overall the mix of classes and ethnicities feels dynamic rather than exploitative. I shopped in a Latin American store, drank cafe con leche and bought okra and plantains from a Caribbean fruit stall piled high with breadfruit and scotch bonnet peppers. I knew where we were eating lunch the second I clocked Tasty K Guyanese Roti Shop, a brightly decorated caravan with tables set up roadside.

Tasty K had as little space as the ambulance from the night before, but the food could not have been more different. For a start, this meal was clearly cooked with love. A chalkboard menu gave a basic idea of the dishes available, but it was really about the specials of the day. No goat, sadly, but curry oxtail or chicken were available, plus a range of filled roti with several vegetarian options. I had oxtail curry with rice and peas, which was succulent, slow cooked and plentiful. We also ordered a spinach roti and I watched while the owner rolled the paratha-style bread by hand. It was delicious: meltingly soft chewy bread encasing rich braised spinach topped with some fierce scotch bonnet sauce. Roti are part of the Indian influence on Guyana, but the rice and peas and the hot sauce are fully Caribbean.

And of course, instead of paying £35 (still horrified by that one) the dishes cost between £3 and £5 each. Sadly, Tasty K is moving from next week and the nice lady didn’t know exactly where they’d be going. Maybe, like the Korean taco truck in Los Angeles, they need a twitter feed to tell loyal customers where to look? That would be a mix of street food and hip social media I could get behind.

Rambulance in the Urban Physic Garden, 100 Union St, London SE1 0NL (cafe open through summer)

Tasty K Guyanese Roti Shop, Station Rd, Brixton, London SW9 8PD (for now)