Heat the oven to 200C/400F/gas mark 6. Cut the onions in rough chunks and place on a roasting tray, spray about 10 times with FryLight Cut the peppers in half, remove the seeds then place face down in the roasting tray. Put into the oven and cook for 30 minutes until the onions are brown and the peppers are tender. Set aside to cool.
Slice the aubergine thinly and spray both sides of the slices with FryLight. Heat 2 large non-stick frying pans and cook the aubergines on a medium-high heat until lightly golden and tender. Remove and cool.
For the bean mixture put the beans and roasted onions into a food processor with the garlic and chopped basil and briefly whiz until finely chopped but not smooth, season.
For the pepper mixture, remove the skins from the peppers, roughly chop and put into the clean food processor bowl with the garlic, feta cheese and black olives, whiz until the pepper is finely chopped
Line a loaf tin, measuring about 22cmx10cm (8½” x 4”) with cling film, overlapping sides. Arrange the cooked aubergine slices, slightly overlapping in the bottom and around the sides of the tin, there should be some left to cover the top. Spread half the bean layer evenly in the bottom of the tin, spoon over the pepper mixture then add the rest of the bean mixture.
Level the top and cover with a layer of aubergine. Cover with cling film and refrigerate overnight. To serve, remove the cling film. Invert onto a flat plate and peel off cling film from terrine, cut into slices with a serrated edged knife.