Heat oven to 200c/fan 180c/gas 6. Sit the chicken breasts snugly in a
small roasting tin, then drizzle over half of the lemon juice. Sprinkle over the
lemon zest, rosemary and some salt and pepper. Roast for 20 mins until
golden brown and cooked through.
Meanwhile, cut the focaccia into bite-size cubes and spread out on
a baking sheet. Sprinkle over the cheese and bake for 15 mins, turning
occasionally until crunchy and golden.
Lift out the chicken and thickly slice. Stir the remaining lemon juice and
the olive oil into the tin, scraping up any nice brown bits from the bottom.
Place the chicken in a very large serving bowl with the lettuce leaves,
avocado, croûtons, peppers and chives. Add the lemony juices, toss well
together, then serve just warm.