Finely slice the spring onions and separate the whites from the green tips. Add the green tips to a bowl.
Finely chop the herbs, olives, and preserved lemon (remove pips). Combine with olive oil and chilli flakes.
Trim and slice the asparagus and broccoli. Boil 400ml water.
Sauté spring onion whites, asparagus and broccoli in olive oil and salt for 4–5 minutes.
Add water and stock cube, simmer for 5 minutes.
Add spinach until wilted. Remove from heat. Add zest and juice of one lemon. Season to taste.
Serve soup topped with the herby salsa, more lemon zest and juice, black pepper, chilli flakes, and olive oil.
