Heat your oven to 160°C/Fan 140°C/Gas 3. Line a baking tray with foil or greaseproof paper. Slice the tomatoes into wedges and slide onto the tray. Season with salt and pepper and toss with 1 tbsp oil. Pop into the oven and bake for 30 mins.
While the tomatoes bake, peel and thinly slice the onion. Peel and grate the garlic. Halve the chilli lengthways, flicking out the seeds and pith for less heat, and finely chop it.
Add 1 tbsp olive oil to a large pan and set over a medium-low heat. Add the onion, garlic, chilli and a good pinch of salt and pepper. Cook gently for 5 mins till softened. Tip in the cannellini and borlotti beans, including the juices from their tins. Stir to combine, then partly cover with a lid and cook for 15 mins, stirring every now and then.
While the beans simmer, break the woody ends from the asparagus spears and discard them (bend the spears and they will snap in the right place).
Set 2 plates on your worktop. Tip the breadcrumbs onto 1 of the plates, and break the egg into the other then beat it with a fork to break it up. Dip an asparagus spear in the beaten egg till coated all over, then roll it in the breadcrumbs. Repeat with the rest of the asparagus.
Stir the spinach into the beans and cook for a further 2-3 mins till wilted. Taste and add a little more salt or pepper if needed. These are your Roman beans. Set aside with the lid on the pan to keep warm.
While the beans finish cooking, set a large frying pan over a medium heat and warm for 2 mins. Add 1 tbsp olive oil and the asparagus. Fry for 3-4 mins, turning a couple of times, till golden.
Spoon the Roman beans into warm bowls. Tear up the mozzarella and scatter over the top, along with the baked tomato wedges. Finish with the fried asparagus spears.