Delia Smith Lasagne Vegetarian

It’s funny how some dishes just feel like a Sunday, isn’t it? Lasagne is one of those for me — especially this one. No meat, no pretence, just layers of soft roasted veg, sweet-tangy tomato sauce, and a proper thick cheese topping that bubbles up golden and proud. I first made this Delia Smith vegetarian lasagne on a grey January afternoon when the fridge looked a bit sorry for itself, and it honestly turned the day around.

There’s something grounding about chopping veg and building a lasagne from scratch. You’re not rushing — you’re making something that matters. Something you’ll sit down with, probably in pyjamas, fork in hand, thinking, yep, this’ll do. Also, it reheats like a dream, which is saying something because I don’t love leftovers. But this? I make extra on purpose.

Why You’ll Love It

• Hearty but not heavy — roasted sweet potato adds richness without making you feel sluggish.
• Layers of flavour — literally and figuratively. The tomato sauce is spicy, sweet, and punchy.
• Cheese sauce is homemade and foolproof — none of that thin, sad stuff.
• It’s make-ahead magic — perfect for meal prep or feeding a crowd.
• You can sneak in almost any veg — it’s flexible like that.
• It freezes like a champ — slice it, stash it, enjoy it midweek.

Ingredients

Veg & Sauce Layers:

• 2 red or yellow peppers, chopped (big chunks, about 2cm)
• 1 courgette (roughly 300g), chopped
• 1 large sweet potato, peeled and diced
• 3 tbsp extra virgin olive oil
• Salt & black pepper
• 1 onion, finely chopped
• 2 garlic cloves, crushed
• ½ tsp chilli flakes (or more if you’re feeling bold)
• 2 x 400g tins chopped tomatoes
• 2 tsp Italian seasoning or dried oregano
• 1 veg stock cube
• 200ml cold water
• 100g fresh spinach (optional but lush)

Pasta & Cheese Layers:

• 9–10 dried lasagne sheets (or however many fit your dish)
• 75g plain flour
• 75g butter
• 750ml milk (semi-skimmed or whole — both work)
• 125g mature cheddar, grated
• 75g mozzarella (or more cheddar, if that’s what you’ve got)

How to Make It

Roast the veg until sweet and golden:

Preheat the oven to 200°C (180°C fan). Toss the chopped sweet potato, peppers, and courgette with 2 tbsp oil, salt, and pepper. Spread them out on a baking tray and roast for about 30 mins until tender and lightly browned at the edges.

Build your tomato base:

While the veg roasts, heat 1 tbsp oil in a pan. Add the onion and cook slowly for 5 mins. Stir in the garlic and chilli flakes — just until fragrant. Add tomatoes, oregano, stock cube (just crumble it in), and water. Simmer gently for 10 minutes. It’ll smell amazing.

Stir it all together:

When the veg are done, stir them into the tomato sauce. If using spinach, chuck it in and let it wilt — only takes a minute or two. Add a bit more salt and pepper if it needs it. Taste is everything here.

Make the cheese sauce thick and lovely:

In a saucepan, combine butter, flour, and milk over medium heat. Whisk it like you mean it until smooth and thick. This bit takes patience — it thickens around minute 7, don’t panic before then. Stir in most of the cheese (keep some back for the top) and season.

Time to layer like a lasagne legend:

In a big oven dish, add a third of the veg sauce. Then pasta sheets. Then another third of the sauce. Then just under half the cheese sauce. Repeat with pasta, veg sauce, and top it all with the last of the pasta and cheese sauce.

Top it and bake:

Sprinkle the reserved cheese on top and bake for 35–40 minutes, until the top is golden and the edges are bubbly and slightly crisp. Let it rest for 5–10 minutes before cutting — trust me, it holds together better and won’t burn your mouth (learned the hard way).

Common Mistakes and How to Dodge Them

Why is my béchamel lumpy?
Don’t stop whisking, especially in the first few minutes. And add the cheese only after it thickens.

The pasta’s still tough — what gives?
Make sure each sheet is fully covered in sauce, or it won’t soften properly. Overlapping is fine.

It’s a bit dry — how do I fix that next time?
Add a little extra tomato sauce or béchamel. Or cover with foil for the first 20 minutes of baking to keep moisture in.

I ran out of cheese mid-recipe — what now?
Use whatever you’ve got. Even cream cheese blobs on top work in a pinch. No shame in improvising.

Storage and Reheating

• Fridge: Keeps up to 3 days, covered.
• Freezer: Slice and wrap individual portions. Reheat straight from frozen or thaw overnight.
• Oven: Cover with foil and heat at 180°C for 20 minutes.
• Microwave: Heat slices on medium for 2–3 mins. Texture won’t be as crisp, but still tasty.

Frequently Asked Questions

Can I make it gluten-free?
Yep. Use GF lasagne sheets and swap the flour in the béchamel for a gluten-free blend.

What else can I add?
Mushrooms, aubergines, even a tin of lentils. It’s flexible — just don’t skip the sauce.

Can I make this ahead of time?
Absolutely. Make it a day ahead, keep it in the fridge, and bake when ready. It might need a few extra minutes if chilled.

Is it spicy?
Not really — the chilli just adds warmth. But if you’re nervous, use a pinch or skip it entirely.

Nutrition Facts (Per Serving)

• Calories: 295
• Fat: 17g
• Carbs: 18g
• Protein: 18g
• Sodium: 444mg
• Sugar: 3.8g

More Delia Smith Recipe:

• Delia Smith Vegetarian Goulash
• Delia Smith Puttanesca
• Delia Smith Carbonara