Step 1

Preheat oven to 220C/200C fan forced. Line a baking tray with baking paper.

Step 2

Place the sweet potato and desiree potato on prepared tray. Drizzle over 2 tablespoons oil and season. Bake for 40 minutes or until golden and tender.

Step 3

Meanwhile, heat a chargrill pan over medium-high heat. Drizzle 1 tablespoon of remaining oil over the corncobs. Cook, turning, for 7-8 minutes or until charred and tender. Set aside to cool slightly then use a sharp knife to cut down the length of the corncob, close to the core, to remove the kernels. Repeat with remaining corncob.

Step 4

Place the potato mixture in the base of a 2.5L (10 cup) glass serving dish. Layer with the tomato, beans, corn, avocado and spinach. Drizzle over dressing. Serve topped with cheddar, shallot, corn chip, coriander and a dollop of sour cream, if using.