Lentil salad with char grilled mushrooms & asparagus

Ingredients (serves 4): 1 x 400g can brown lentils, rinsed, and drained 1/2 small red onion, finely chopped 1 tbs balsamic vinegar Pinch of caster sugar Olive oil spray 4 large flat mushrooms, trimmed 2 bunches asparagus, woody ends trimmed, halved crossways 1 large char grilled red (green pepper), cut into thin strips 1/2 cup…