Vegetable Gratin

Ingredients (serves 6)

• 2 large (about 320g) parsnips
• 250g orange sweet potato (kumara)
• 2 small leeks, white section only
• 30g (1 1/2 tbs) butter, melted
• 2 garlic cloves, chopped
• 1/2 tsp dried thyme
• 1/4 tsp salt
• 1/4 tsp ground white pepper
• 20g (1 tbs) butter, extra
• 25g (1/2 cup) fresh breadcrumbs
• 1/4 tsp dried thyme, extra
• Extra salt & ground white pepper, to taste

• Basic bechamel sauce (Makes 4 cups)

• Melted butter, for greasing
• 1000mls (4 cups) milk
• 2 bay leaves (see note)
• 2 thick slices unpeeled brown onion
• 60g (3 tbs) butter
• 5 tbs plain flour
• 1/2 tsp salt
• 1/2 tsp ground white pepper (see note)
• Pinch ground nutmeg

My own choice of vegies

Method

1. Preheat oven to 200°C.
2. Peel and cut the parsnips and sweet potato into 6cm lengths and then into 1.5cm-thick sticks. Halve the leeks lengthways and cut into 6cm lengths. Wash and drain the leeks well.
3. Place the parsnips, sweet potato, leeks, butter, garlic, thyme, salt and pepper in a large bowl and toss to combine. Place vegetables in a 5.5cm deep, 20cm round (base measurement), 1.5-litre (6-cup) ovenproof dish, moving the vegetables around so they fit snugly. Place the dish on a baking tray. Cover the dish with a lid or foil and roast in preheated oven for 30 minutes.
4. Meanwhile, make basic bechamel sauce (see Microwave method under notes): Fold the bay leaf down the centre vein to release the natural oils and aroma. Choose a medium, about 3.5-litre (14-cup), 20cm diameter (inside measurement) saucepan to cook the sauce. The milk will heat more quickly and evenly than if using a small saucepan.
5. Place the milk, bay leaf and onion in a medium saucepan over medium heat and bring to the boil. The quantity of milk required depends on how thick or thin the sauce needs to be. Take the saucepan off the heat when tiny bubbles of milk appear around the edge. Set aside for 5 minutes to cool slightly. This initial heating helps to speed up the final cooking of the sauce. When the milk cools slightly, the bay leaf and onion further infuse the milk (which will subtly flavour the sauce) and lumps are less likely to form when whisking it into the roux. Strain milk into a heat-resistant jug and discard the bay leaf and onion.
6. Melt the butter in a clean saucepan (you can wash and re-use the same saucepan used to heat the milk if you like) over medium heat until foaming. Add all the flour at once and stir over heat with a whisk or wooden spoon for 1 minute or until the roux leaves the side of the pan and is bubbling. Don't allow the roux to brown.
7. Take the saucepan off the heat and place onto a wet dishcloth, damp tea towel or cork mat to prevent it from slipping. Add 1/2 the warm infused milk while stirring constantly with the whisk. Stir vigorously until the mixture is smooth and free of lumps. Gradually add the remaining milk, stirring until smooth. It is important that the milk is thoroughly mixed into the roux or the sauce will become lumpy. If you do not have a whisk, a wooden spoon can be used but instead of adding 1/2 the milk to the roux initially, add about 80mls (1/3 cup) at a time until 1/2 the milk is added, then continue as if using a whisk.
8. Place the saucepan over medium heat and stir constantly until the sauce thickens and comes to the boil. It is important to keep stirring as the sauce comes to the boil. This evenly distributes the heat and ensures the sauce is smooth and free of lumps. Once the sauce reaches boiling point, reduce heat to low and allow the sauce to simmer, uncovered and stirring occasionally, for 3 minutes. This extra cooking removes any floury taste from the sauce and will further thicken it slightly. Remove the saucepan from the heat and allow the bubbles to subside before seasoning with salt, pepper and nutmeg. It is best to season the sauce after removing it from the heat so the pepper does not form small clumps and a fresher aroma from the nutmeg is retained.
9. Place the prepared sauce cover directly onto the surface of the sauce and keep the sauce at room temperature.
10. Meanwhile, heat the extra butter in a small frying pan or saucepan over medium heat until foaming. Add breadcrumbs and stir constantly with a wooden spoon until just starting to colour. Stir in extra thyme and then season with extra salt and pepper.
11. Remove the vegetables from the oven and pour the bechamel sauce evenly over the vegetables. Sprinkle with the breadcrumb mixture. Return to the oven and bake for a further 15-20 minutes or until the vegetables are tender, the topping is browned and the edges are bubbling. Serve immediately.

Notes

• 
  A fresh or dried bay leaf may be used.
  It is preferable, but not imperative, to use ground white pepper to avoid black specks in your sauce.
  Basic Bechamel Sauce: Microwave method: Place the milk, bay leaf and onion in a medium heat-resistant microwave-safe jug. Heat, uncovered, for 3-4 minutes on High/800watts/100% or until the milk comes to the boil. Set aside for 5 minutes to cool slightly. Strain and discard the bay leaf and onion. Place the butter in a large heat-resistant microwave-safe bowl and heat, uncovered, for 1 minute on High/800watts/100% or until melted and foamy. Add the flour, whisk to combine, return to the microwave and cook for 30 seconds on High/800watts/100%. Add strained milk, a little at a time, whisking constantly. Return to the microwave and continue to cook the sauce, uncovered, whisking every minute, for a further 4-6 minutes on High/800watts/100% or until the sauce boils and thickens.