3yellow-fleshed potatoes, such as Nicola, Charlotte or pink-eye (about 150gm each), unpeeledFor deep-frying:vegetable oil1snapper fillet (about 800gm), pin-boned, skin scored into 8 pieces1 tbspolive oil200 gmyoung Roman beans, tailed and halved widthways50 gmbutter, coarsely chopped3garlic cloves, finely chopped300 gmassorted mushrooms, such as wood-ear, chestnut and enoki, trimmed1 tspwhite wine vinegar80 mlwhite wine
Scrub potatoes and place in a saucepan with enough cold water to cover. Bring to the boil, cook until parboiled (6-8 minutes). Drain, then, when cool enough to handle, cut into quarters and squash with your hand, set aside.
Preheat vegetable oil in a deep-sided saucepan or deep-fryer to 180C. Heat a large non-stick frying pan over medium high heat. Brush snapper with olive oil, season to taste and cook, skin-side down, pressing lightly, until cooked most of the way through (4-8 minutes), then carefully turn and cook until just cooked through (1-2 minutes). Keep warm.
Meanwhile, deep-fry potatoes in vegetable oil until golden and crisp (5 minutes), drain on absorbent paper, set aside and keep warm.
Meanwhile, blanch beans (3 minutes), drain, set aside, keep warm.
Heat a separate frying pan over high heat, add butter and garlic, and when foaming add mushrooms and stir occasionally until tender (1-2 minutes). Deglaze with white wine vinegar, then wine, and cook until reduced(2-4 minutes). Serve fish immediately with Roman beans, potatoes and mushrooms.