Preheat your oven to 200°C/Fan 180°C/Gas 6. Fill and boil your kettle. Trim and scrub the carrots and slice them into thin batons. Peel the red onions and slice them into thin wedges. Scatter the carrots and red onions into a large roasting tin. Pour in 1 tbsp olive oil and season with a pinch of salt and pepper. Slide the veg into the oven and roast for 25 mins, till tender and slightly caramelised.
Meanwhile, tip the pearl barley into a pan with a pinch of salt. Top up the pan with 200ml boiling water. Bring to the boil, then reduce to a simmer, cover with a lid and cook for 20-25 mins, till the barley is tender.
Peel and grate the garlic into a bowl. Add 1 tbsp each honey, wholegrain mustard and olive oil, 2 tsp cold water and a pinch of salt and pepper. Stir together into a dressing.
Drain the barley and tip it into a mixing bowl. Add the lamb's lettuce, roasted carrots and onions. Toss with the dressing.
Divide the salad between a couple of plates. Top with dollops of the ricotta and serve.