Preheat the oven to 200 xxx. Trim the roots and woody greens off the leeks, rinse out any grit, then slice them into 1cm-thick half moons. Place a shallow oven-proof casserole dish on a medium heat and gently warm 1tbsp olive oil. Add the leeks with a pinch of salt and fry, stirring often, for 8-10 mins till soft and bright green.

Remove the leeks from the pan. Pour in 2 tbsp olive oil and add 2 tbsp plain flour. Gently whisk for 2 mins to form a paste. Cook for a further 1 min then slowly pour in the oat drink, little by little. Keep whisking as you add the oat drink till you have a smooth sauce. Continue to cook for 5-10 minutes or till the sauce has thickened.

Zest the lemon and set aside. Squeeze the juice from the lemon into the sauce and add the wholegrain mustard. Stir in half of the Julietted cheese alternative. Season with a pinch of salt and pepper. Return the beans and leeks to the pan. Reduce the heat to low for 5 mins to allow the flavours to meld and the cheese alternative to melt,

Meanwhile, prepare the crunchy herb topping. Pick the thyme leaves off the woody stalk, add to a blender with the lemon zest and sourdough croutons. Add 2 tbsp olive oil and a large pinch of salt. Blitz for 30-45 seconds to form a herby crumb.

Scatter the crumb on top of the bean mixture and sprinkle over the remaining cheese. Place the dish in the oven. Bake for 35 mins till golden and crispy on top and bubbling around the sides.

Remove from the oven and allow to sit for 5 mins before serving.