Use a clean cotton tea towel to pat down your washed and drained green beans so they have completely dried before you begin.
Make your garlicky butter bean purée first by transferring the drained butter beans, chopped garlic cloves, sea salt, onion powder, and extra virgin olive oil to a blender, blend until you have a fairly smooth consistency, then spread it over a large serving plate.
To a large wok (or skillet) over high heat, pour in a tablespoon of olive oil and heat the oil until shimmering.
Add the almond slivers to the wok and continuously stir-fry until they start to change colour, about a minute, more or less. As soon as the almonds turn golden brown, remove the wok from the heat and slide the slivers into a dish. It doesn’t matter if some are browner than others, it’s better that they don’t burn.
Pour the remaining tablespoon of olive oil into the wok and when it shimmers add the green beans. Stir-fry the beans periodically, not continuously, as you want the beans to remain in one place long enough to begin to blister.
Stir-fry for 2-3 minutes or so for bright green tender beans, which are only blistered in parts (as pictured). If you prefer softer, charred olive-coloured beans, stir-fry for 8-10 minutes.
When the beans are blistered to your liking, remove the wok from the heat. Season the beans with a pinch of salt, return the slivered almonds to the wok and stir to combine.
Use tongs to pile the blistered green beans onto the white bean purée, scrape the remaining almonds onto the top of the beans, drizzle on the extra virgin olive oil, and serve immediately.