Heat the oven to 190C (170C fan)/gas 5. Put the squash, onion and fennel seeds in a large roasting tray with three tablespoons of oil, and season. Roast for 30-40 minutes, until everything is really soft and golden.
Meanwhile, in a bowl or large jug, whisk the eggs, flour, milk, poppy seeds, herbs and a good pinch of salt and pepper, until you have a smooth batter. Set aside to rest until the veg are ready.
Once cooked, remove the onions and squash from the oven and add a quarter to a frying pan to make the mustard and ale gravy (see below).
Turn up the oven to 230C (210C fan)/gas 8. Put five tablespoons of oil and the remaining squash and onions in a high-sided, 20cm x 25cm dish, and pop in the oven for five to 10 minutes, so the oil gets really hot and the oven comes up to temperature.
Carefully remove the dish from the oven and, working quickly so the oil stays hot, pour the batter evenly over the hot veg and oil. Top with chunks of bread and a few extra sprigs of rosemary, and bake for 20-25 minutes, until risen, golden and crisp – do not open the oven door in the first 20 minutes or the yorkshire crust will not rise well.
Meanwhile, make the gravy and steam some greens. When the toad in the hole is ready, remove from the oven and serve immediately.