Trim any tough ends and slice the mushrooms lengthways into even strips about 5–7 mm thick.
Heat the oven to 180°C fan, spread the mushrooms in a single layer on a lined tray, and bake for 8–12 minutes until softened and slightly wilted with no browning, then cool for 5 minutes.
Whisk together the soy sauce or tamari, Worcestershire sauce vinegar, maple syrup or honey, smoked paprika, garlic powder, onion powder, black pepper, and chilli flakes. Crush the fresh garlic with a small pinch of salt until paste-like, then stir it into the marinade.
Add the mushrooms to the marinade, toss thoroughly, cover, and refrigerate for 24–36 hours, stirring or turning once or twice for even colour.
Drain the mushrooms in a colander for 3–5 minutes, then blot lightly with kitchen paper so they’re coated but not dripping; remove any large garlic pieces clinging to the surface.
Arrange the mushrooms in a single layer on dehydrator trays with a little space between pieces and dry at 50°C for 5–7 hours, rotating trays halfway if your dehydrator dries unevenly.
Start checking after about 4–5 hours; they’re done when darker, leathery, and pliable, bending without snapping and feeling dry through the centre of thicker strips.
Cool completely before packing, then store airtight in the fridge.