Preheat the broiler and set the shelf to the lowest position. Cover a baking tray with foil and grease it lightly with oil. Combine the nuts, carrots, parsley, garlic, lemon zest and ground coriander in a food processor and process until finely ground. Add the beans and scallions and briefly pulse the mixture, to chop the onions and crush the beans. Season to taste.
Divide the mixture into four and shape each portion into a patty about 10 cm wide and 2 cm thick. Place on the baking tray. (The patties can be prepared ahead, cooked or uncooked, and kept chilled, if more convenient.)
Brush the patties with half the oil, then grill for about 5 minutes until well browned and sizzling around the bottom. Turn them over and brush with the remaining oil, then grill for a further 5 minutes. Reduce the heat to medium and turn over once again. (They tend to crack and may spread slightly, so pat them gently to keep them neat.) Grill for a final 5 minutes or until browned. Pat the patties into shape, if necessary, and leave to stand for 2-3 minutes to firm up.
Meanwhile, coarsely grate the apples into a bowl. Stir in the apricots, chutney and lemon juice. Toast the cut sides of the burger buns.
Put a little arugula and cucumber on the bottom of each bun, add a patty and top with a spoonful of the chutney and a couple of onion rings. Replace the tops of the buns and serve, adding the remaining chutney and salad.
Each serving: 17 g protein, 33.5 g fat of which 6 g saturates, 73.5 g carbohydrate, 15.5 g fibre, 687 Calories