Start by making the batter. In a large bowl, thoroughly whisk the eggs and milk together, until foamy. Add the mustard and salt and sift over the cornflour and plain flour. Whisk again until you have a smooth mixture and set aside for 30 minutes.
Meanwhile, heat the oven to 220°C, 200°C fan, gas mark 7. Cut the carrots and aubergine into small wedges, removing any aubergine stem. Place them in a baking dish, roughly 25cm x 21.5cm in size, drizzle over the olive oil and season well. Shuffle the vegetables around so that they’re evenly covered in the oil and sitting in a single layer, then place the tin in the oven and roast for 15 minutes.
Remove the tin from the oven and place the vegetables to one side in a bowl. To that same tin, add the vegetable oil. Place the tin back in the oven for about 7 minutes, or until you can see it shimmering because it’s hot.
Moving quickly and carefully, remove the hot tin from the oven. Pour the batter into the tin and top with the roasted veggies, whole cherry tomatoes and sprigs of rosemary. Place the tin back in the oven for 25 minutes, or until the toad in the hole is puffed and golden.
Empty a packet of Bay’s Kitchen Vegetable Gravy with Thyme & Chives into a pan and heat gently until piping hot. Serve drizzled over the toad in the hole.