Heat your oven to 200°C/Fan 180°C/Gas 6. Peel and slice the onion. Peel and grate or crush the garlic. Add ½ tbsp olive oil to a large pan over a medium heat. Add the onion and bay leaf. Season with a pinch of salt and pepper. Fry and stir for 5 mins till softened.
Add the garlic. Cook and stir for 1 min. Tip in the tomatoes. Cover and gently simmer for 15 mins till the sauce has started to thicken. Add 1 tbsp balsamic vinegar. Stir to mix.
While the sauce simmers, finely chop the chilli (flicking out the seeds and white bits for less heat) and strip the leaves from the thyme sprigs. Add the chilli and thyme to the sauce. Cook for 10 mins till thick. Stir now and then. Taste and adjust the seasoning.
Zest the lemon and set to one side. Slice the aubergines into thin rounds and pop in a bowl. Squeeze a little lemon juice from half the lemon over the aubergines. Pour over 2 tbsp olive oil to coat. Season with salt and pepper.
Gloss a large frying pan with ½ tbsp oil. Fry the aubergines over a high heat in batches for 2 mins till golden on each side. Add ½ tbsp more oil as needed.
In 2 small baking dishes (or 1 medium dish), layer the aubergine and then the sauce, repeating till everything’s used up. Top with the breadcrumbs and a grind of pepper.
Bake for 10-15 mins or till golden on top. While the bake cooks, drain and rinse the butter beans. Heat a small frying pan and toast 2 tsp fennel seeds for 1 -2 mins.
Juice the remaining lemon half into a jug and whisk with the lemon zest, seasoning and ½ tbsp olive oil. Toss through the butter beans with the fennel seeds. Pile on top of the salad leaves and serve alongside the aubergine bake.