First, pour the milk into a small saucepan. Add the bay leaf, garlic clove and onion. Bring to the he simmer, then take off the heat, cover and set aside to rest.
Cook the mince according to the packet instructions, then set aside.
Finely chop the onion, carrot and red pepper.
Heat the olive oil in a saucepan and gently fry the onion until soft. Add the carrot and red pepper, then sauté for 5 minutes, stirring regularly.
Stir in the garlic, tomato purée and dried herbs for a few seconds, then add the tomatoes and stock.
Bring to the boil, then simmer for 15 minutes. Add the green beans and cook for another 5 minutes, under cover. Stir in the mince and the drained tinned beans, then the chopped parsley. Cook for a couple of minutes, then turn off the heat. Set aside, chill if you’re making the lasagne later.
When you’re ready to make the lasagne, preheat the oven to 180°C.
Make the white sauce. Remove the onion, garlic and bay leaf from the milk.
Heat the oil in a pan and fry the corn starch for a minute, then add a ladleful of the infused milk. Keep stirring until you get a lump-free paste. Add more milk if necessary. When you get a thick paste, add this to the milk together with the nutritional yeast flakes or grated cheese and gently bring to a simmer. Keep stirring until you get a thick, smooth cream (like custard). Season with salt and pepper to your liking.
Spoon about a third of the vegetable filling into a deep baking dish and spread it out evenly. Top with a layer of lasagne sheets. Add another third of the vegetable mixture then a second layer of lasagne sheets.
Pour over half of the white sauce, then the remaining vegetable mixture. Finish with a final layer of lasagne and the rest of the white sauce. Scatters some grated vegan cheese on the top.
Bake for 35 minutes, until the top is golden and bubbling.
Rest for 5 minutes before serving.