Claire's Green Veg Crumble - Veg Power

Ingredients

• 350g frozen broccoli florets (or 1 head fresh - cauliflower works great here, too, as does a mix of the two)
• 250g frozen chopped spinach or frozen whole baby leaf spinach
• 225g frozen peas
• 1 large courgette, grated
• 3 tablespoons unsalted butter
• 3 tablespoons plain flour
• 400ml milk
• 400ml stock (or more milk)
• 1/2 teaspoon mustard powder (or 1 teaspoon mustard)
• small pinch nutmeg or allspice (about 1/4 teaspoon)
• salt & pepper, to taste
• large handful of grated cheese (about 50g)
• 100g wholemeal flour
• 200g oats
• pinch sea salt (about 1/4 teaspoon)
• 110g unsalted butter, room temperature and cubed
• handful of chopped nuts (pecans, walnuts, hazelnuts or almonds all work well)
• handful of seeds (sunflower and pumpkin work really well)
• a little more grated cheese to top, optional