Vegetable lasagna

• 9 sheets (about 180 g / 6 oz)dried lasagna sheetsmade from wheat and no egg (check the label: fresh lasagna sheets and some dried ones contain egg). If yours contain egg, offer this only once your baby has had well-cooked egg on its own without a reaction, on a day they're well, at home, when you can watch them for a couple of hours afterward
• 1onionfinely chopped
• 2 mediumzucchini (courgettes)
• 1 mediumcarrot
• 1 can (400 g / 14 oz)chopped tomatoesno salt added
• 1 tbsptomato paste (purée)check the label for no added salt
• 100 ml (scant ½ cup)water
• 1 tbspolive or vegetable oil
• 100 g (3½ oz)fresh spinachor the same weight of frozen spinach
• 250 g (1 cup)whole-milk ricottamade from pasteurized milk (check the label)
• 40 g (⅓ cup)grated mozzarellamade from pasteurized milk; a thin layer for the top

Steps

1. 1Wash your hands. Scrub the carrot under running water, peel it and grate it finely. Rinse the zucchini, trim the ends and grate them. Rinse and peel the onion, then chop it finely. Rinse the spinach, remove any thick stems, then wilt it in a pan with a splash of water for 2 to 3 minutes (cook frozen spinach until it's steaming hot all the way through), squeeze out the water and chop it very finely, with no whole leaves or long strands left. Check both cheese labels say made from pasteurized milk. Heat the oven to 190°C (375°F).
2. 2Heat the oil in a large pan over medium-low heat and cook the onion gently for about 10 minutes, until very soft and see-through. Add the carrot and zucchini and cook for 5 minutes more. Stir in the tomatoes, tomato paste and water, and simmer, partly covered, for 15 to 20 minutes, until the vegetables are very soft and the sauce is thick. Don't add salt.
3. 3Meanwhile, boil the lasagna sheets in unsalted water, a few at a time so they don't stick, for a few minutes longer than the package says, until a piece squashes easily between your fingers. Lay them flat on a clean, damp tea towel. Stir the spinach into the ricotta with 2 to 3 tablespoons of water so it spreads easily.
4. 4Spread a thin layer of sauce in a baking dish, then layer sheets, half the ricotta, a third of the sauce, more sheets, the rest of the ricotta, more sauce, the last sheets and the rest of the sauce. Scatter the mozzarella thinly on top.
5. 5Cover with foil and bake for 30 minutes, then uncover and bake for 10 to 15 minutes more, until the sauce bubbles at the edges and the middle reaches 165°F (74°C) on a food thermometer.
6. 6Let the lasagna rest for 15 minutes so the layers set. Take your baby's portion from the middle of the dish, leaving off crisp edges and any thick, stringy cheese, and cut any stretchy cheese strings short. Spread it on a plate to cool, and check the middle of the portion is only just warm before serving: layered dishes hold heat inside.