This is a pescatarian version of an old trick in which I push anchovies into legs of lamb to flavor the meat as it roasts. Because the cauliflower is roasted whole, it’s a bit showy, like a piece of roast meat, and perfect for a vegetable-focused meal that feels celebratory. Serve this on its own as a dinner for two, or alongside a simple green salad for a healthy meal to share.
In a fine-mesh strainer, rinse the anchovies and capers in cold water, then soak them covered with cold water in a small bowl for 10 minutes to remove their salt.
Drain and set aside.
In a medium pan on low heat, fry the bread crumbs with ¼ cup of the olive oil, stirring frequently until they turn golden brown, 5 to 7 minutes.
Drain using a fine-mesh strainer and spread onto a paper towel.
Set aside.
Use a small knife to cut six small rectangular slots into the cauliflower, just large enough to fit a folded anchovy fillet.
Spread the slices evenly on the upper half of the cauliflower.
Fold the anchovies in half and use a small knife to stick them into their slots.
Thinly slice 1 garlic clove.
Cut small slots across the cauliflower just large enough to hold the slices, and push the garlic slices into their slots.
Set the cauliflower in a medium ovenproof pan and coat with the remaining ½ cup olive oil.
Place the remaining two garlic cloves next to the cauliflower.
Top with the capers, lemon juice, and a pinch of salt.
Add ⅓ cup water to the bottom of the pan and bake for 10 minutes.
Remove the pan from your oven and tilt it toward you, allowing the water and olive oil to pool at the bottom.
Scoop the liquid over the cauliflower, basting it.
Return the pan to your oven, continuing to baste the cauliflower every 10 to 15 minutes, until it has browned and cooked through, 45 minutes to 1 hour in total.
Remove the pan from your oven and transfer the cauliflower to your serving dish.
Top with a drizzle of olive oil and any scrapings from the pan, then let cool to room temperature.
Finely grate the egg over the top of the cauliflower.
Sprinkle with the lemon zest, bread crumbs, and parsley.
Slice the cauliflower into slabs and serve immediately.