- Heat the oil in a large saucepan over a medium heat.
- Cook the onion for 5 minutes, stirring. Add the tomato purée and cook for 8 minutes, stirring – this intensifies the flavour.
- Stir in the Madeira and boil for a few minutes. Add the barley, Tabasco and 1 litre stock. Boil, then simmer for 20 minutes to reduce by one-third.
- Bring the remaining stock to the boil in a large saucepan and add the baby onions. Cook for 5 minutes then cool in cold water. Peel. Blanch the other veg (do the potatoes separately) for 3 minutes.
- Lift into a colander to drain well then season and set aside.
- Preheat the grill to medium-high. Put the veg (except the potatoes) in 6 x 300ml pie dishes. Spoon in the sauce and top with overlapping potato slices. Brush with butter and grill on a baking sheet for 8-10 minutes, until golden.
To freeze: Once made, cool, cover and freeze for up to 3 months. Thaw and reheat at 190°C/fan170°C/gas 5 for 20-25 minutes, until piping hot.