Heat a griddle pan until searingly hot. Grill the peppers on both sides until blackened, then transfer to a bowl and cover with clingfilm.
Slice the aubergine and half the courgettes into long strips – if you have any courgette flowers leave them whole. Using the same pan, grill the aubergine, courgettes and their flowers (if using) until slightly charred; transfer to a bowl, season, and drizzle with oil.
Carefully peel the skin from the seared peppers and tear them into strips. Add to the bowl with the aubergines and courgettes.
Scrunch the tinned tomatoes in your hands and add to the bowl. Drizzle in the sherry vinegar and a little extra oil if desired. Mix well.
Halve or slice the fresh tomatoes and chop most of the herbs, leaving a few leaves whole. Slice the remaining uncooked courgettes into rounds and toss in a separate bowl with the fresh tomatoes, herbs and mizuna. Season and drizzle with olive oil. Serve the two salad bowls together with grilled lamb or goat’s cheese.