Spray a baking sheet lightly with spray oil. Put the oats and nuts in a bowl and stir in the maple syrup. Spread the mixture out on the prepared baking sheet and bake in a preheated oven, 180°C (350°F), Gas Mark 4, for 5 minutes.
Remove from the oven and stir well. Return to the oven and bake for a further 3–4 minutes until lightly toasted. Leave to cool.
Divide the granola between 4 serving bowls and pour over the milk. Add the berries and serve with Greek yogurt and a drizzle of maple syrup.