Put the sundried tomatoes in a small bowl. Just cover them with boiling water. Leave to soak for 15 mins.
Heat your oven to 180°C/Fan 160°C/Gas 4. Rub the chicken breast pieces all over with a good pinch of the harissa powder (more if you like it hot, but be careful – it's spicy), some salt and pepper and 1 tsp olive oil. Pop into a large ovenproof dish.
Halve the cherry tomatoes and tip into a bowl. Peel and grate the garlic. Add to the bowl with 1 tsp olive oil. Season generously. Toss together to mix.
When the sundried tomatoes are soft, drain well, roughly chop them and mix with the cherry tomatoes. Add the tomato mix to the roasting dish, tucking it in any gaps around the chicken. Slide the baking dish to the oven for 15 mins, or till the chicken is cooked through.
Zest and juice the lime into a small bowl. Pour in 1 tbsp olive oil. Sprinkle in a little seasoning and stir well till combined.
Drain the lentils and rinse with cold water. Shake away any excess water. Tip the lentils into a bowl and dress with most of the lime dressing. Add a pinch of salt or pepper if you think it needs it.
Heat a griddle or frying pan till smoking hot. Quarter the lettuces lengthways. Cook for 1-2 mins on each side, till they're charred and lightly wilted. Remove from the pan. Spoon the remaining dressing over the lettuces.
Divide the lentils between 2 warm plates. Arrange the chicken on top along with some of the tomatoes. Finish with a few of the charred lettuce quarters and dig in.