1. Preheat the oven to 180°C/350°F/gas 4.
2. Peel and finely slice the garlic and put it into a medium pan on a medium heat with the butter.
3. When the butter has melted, stir in the flour for a minute to make a paste, then gradually add the milk, whisking as you go, until lovely and smooth.
4. Add the broccoli (cut up first, if using fresh) and simmer for around 20 minutes, or until the broccoli is cooked through and starts to break down, then mash or blitz with a stick blender (adding an extra splash of milk to loosen, if using fresh broccoli). Grate in half the Cheddar and season to perfection.
5. Arrange the cauliflower in an appropriately sized baking dish (cut into florets first, if using fresh), pour over the broccoli white sauce and grate over the remaining Cheddar.
6. Blitz the bread into breadcrumbs in a food processor, then pulse in the thyme leaves and almonds. Toss with a lug of oil and a pinch of sea salt and black pepper, then scatter evenly over the cauliflower cheese.
7. Bake for 1 hour, or until golden and cooked through, then enjoy!