Chargrilled vegetable stacks
Ingredients (serves 4): Olive oil spray 1 brown onion, finely chopped 1 garlic clove, crushed 1 x 400g can no-added-salt diced tomatoes 1 small (about 300g) eggplant, ends trimmed, cut lengthways into four 1cm-thick slices 300g sweet potato, peeled, cut lengthways into four 5mm-thick slices 1 large zucchini (baby marrow), ends trimmed, cut into eight…