Super greens lasagne

Name: Super greens lasagne
Cuisine: European, Italian, Mediterranean
Ingredients: 2 tbsp extra virgin olive oil; 2 tbsp plain flour; 650ml of semi skimmed milk; 60g extra mature cheddar; 200g spinach; 1 head of broccoli, chopped into small florets; 2 leeks, diced; 2 large garlic cloves, minced; 16 finely chopped green olives; 30g fresh basil, stems and leaves chopped separately; 1 chicken stock cube; 100ml water; 1 lemon; Dried lasagne sheets; Parmesan; 2 pre-cooked chicken breasts, shredded