Boston Bake - a meat free recipe using leftovers

This is a great and very adaptable comfort food recipe. Here's how it started life. Many years ago, I used to run a health food store and a specialty was simple vegetarian takeout lunches. The most popular were sandwiches and baked potatoes.

The sandwiches were all made on great wholewheat bread and the most popular toppings for the baked potatoes were baked beans, garlic butter and cheese. (Several customers used to order a baked potato with garlic butter before dental appointments - ha.)

My dilemma was this - I used to prepare these takeout lunches fresh every day but there were always leftovers. I hate waste. On the following day, how could I use yesterday's leftover sandwiches, baked potatoes, cheese, garlic butter and baked beans?

Boston Bake was born

Before long, this was incredibly popular. It was cut into squares (about four inches square) and sold at a great, low price. Students, seniors and other people on fixed incomes loved it because it was cheap and nutritious - especially when served with a green salad and with an apple or other piece of fruit for a quick and simple dessert. Ever since, I have made Boston Bake at home for the family regularly. Sometimes I use leftovers and sometimes I have to start from scratch. One of the things I love about this recipe is that you can add many different leftovers you might have lurking in the refrigerator.

If you have leftover cooked potatoes, you've already completed the first step! If not, cook potatoes by boiling or baking - boiling is quicker. How many? Well, that's one of the great things about this recipe - there are no exact quantities. You'll just need enough slices of potato to line your oven dish, although two layers are fine too. What sort of potatoes? Whatever you have! Large, small, it doesn't matter at all.

And if you have leftover sandwiches, that's step two nearly done. Just roughly chop them or whiz them in a blender or food processor. To start from scratch, take any bread and chop, grate or break into chunks. I usually just break it up with my fingers and use a cheese grater to break up any crusty bits. It doesn't have to be finely grated or chopped as you can see from the photograph.

Then have fun adding whatever you might have around. As you can see, I added lots of freshly-ground black pepper, a little sea salt, some chopped basil from the garden, some chopped (or pressed) garlic and just a little grated cheese. If I'm having one of those days when I don't care about calories, I add a little butter, cut into small pieces.

Here are a few ideas of other things you can add.

• Leftover cooked mushrooms, chopped
• Fresh scallions / spring onions, finely sliced
• Chopped tomato
• Any leftover cooked vegetables you may have - carrots, zucchini, broccoli - anything will work
• Your favorite herbs or flavorings - whatever suits your family's tastes

Put the bread mixture to one side. The flavors will mingle whilst you're preparing the potato base. I grease the oven dish lightly with butter, but you could use a low-calorie spray or olive oil. Use whatever you have to hand. The whole idea of this recipe is that you can make it from ingredients you have in your pantry and fridge; you don't need to buy any special ingredients.

Simply slice the potatoes to line the dish. This can be one layer, two or more - it's up to you and depends on the size of your dish and the amount of potato you have. Notice that I don't peel the potatoes - I don't want to throw away that valuable fiber and the nutrients that are just below the skin. Because we love black pepper, I grind some on top. You can add your own flavorings and herbs. Mint is particularly good with potato.

Just add your bread mixture on top of the potatoes and press down lightly. Notice that the bread I used was a mix. I used one large slice of wholewheat bread and a slice from a lovely olive loaf. You can probably see the black olives in the photograph. Any bread will do but the better quality it is, the better the eventual dish will be. Any bread products can be added - I remember once adding a slice of leftover pizza that I'd run through the food processor!

I use British Heinz Beans because they are our favorite. But again, anything will do. If you've made your own baked beans and have leftovers - fantastic! If they are a cheap brand that was on sale at the grocery store, no problem. Adaptability and flexibility is the key here. Just add the beans on top of the bread mixture.

Be sure to get all the sauce too as this will soak into the bread below. Because I'm truly tight-fisted, I add a little water to the empty can, swill it round to get all the sauce that's clinging to the side of the can, and pour that on top too. (Try the same trick with an 'empty' gin bottle. Add a little tonic, put the cap on the bottle and swill it round to make sure that you get the last remnants of gin - and a free but weak G & T!)

We love cheese so I cover the beans completely. But cheese is high in calories so you might have more restraint than I do! Again, it doesn't matter - just use whatever you have. You can use a mixture of cheeses - just grate them together.

Even hard lumps of cheese that have definitely seen better days can be added. Top with a little Parmesan? Why not? I often have just a little Parmesan left in the tub so that can go in too. Now put the whole thing into a pre-heated oven. I set mine to 350° but if you already have the oven on to cook another dish at another temperature, that's fine and is a good way to make the most of your oven space; it's a shame to use the electricity to heat just one dish so you can plan to make Boston Bake when you're cooking something else if you wish to be truly economical.

Temperature isn't critical here - all you need to do is leave the dish in the oven until the food is heated through and the cheese is melted. This is usually about 20 minutes. Sometimes, I broil the dish for the last couple of minutes to make the cheese golden.

Guess what? I add black pepper before serving! But you can garnish the dish in whatever way you want to.

• Sliced tomato and basil - as I did
• Chopped parsley or parsley sprigs
• Paprika
• Black olives - sliced or whole
• Chopped scallion / spring onion

Did you know that studies show that half - yes, half - the food produced in the world is thrown away? We owe it to the planet to make the most of leftover foods.

Part of the trick of using leftovers is to make sure that they have a different flavour and texture than the previous meal. When you learn more about this type of cooking, your family will never know that they are eating 'recycled' ingredients.

When I decided that I was no longer going to eat meat - and this comment really ages me - there were only a few vegetarian recipe books available. These had been written years previously and had pretty boring recipes for nut roasts and nut cutlets, lentil stews and dishes using textured soya protein. All were boring. Today, whatever sort of cookery ideas you're looking for, there'll be a book to help you and give you some great recipes and brilliant inspiration.

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Meat free tikka masala

Try a Salad Saturday

Have a meat free Irish themed dinner party

All photographs taken by me during the preparation of this dish.