1 quantity Slow-Cooked Tomato Sauce (see recipe below)
3 lb [1.5 kg] mushrooms (I like portobello, white, and crimini)
4 Tbsp [50 g] butter
3 Tbsp olive oil
Approx. 10 to 14 lasagna noodles
For the cheese sauce
4 Tbsp [50 g] butter
1/3 cup + 1 Tbsp [50 g] all-purpose flour, sifted
2 cups [500 ml] whole milk
2 Tbsp Dijon mustard
2 ½ cups [250 g] finely grated Monterey Jack or cheddar cheese
For the topping
1 ½ cups [150 g] finely grated Monterey Jack or cheddar cheese
1 1⁄3 cups [100 g] fried bread crumbs (see recipe below) or panko bread crumbs (optional)
Make the Slow-Cooked Tomato Sauce first so that it is happily simmering away (for a minimum of 45 minutes) while you get on with the rest.
Slice the mushrooms into thirds, then across into cubes. Put a large frying pan over the heat with the butter and oil, and when the butter has melted, add the mushrooms. Don’t let them cook too quickly: the trick is to soften the mushrooms without them losing their plumpness. When they are cooked, take them off the heat and set aside.
For the cheese sauce, melt the butter in a large, heavy-bottomed pan (this is to stop your sauce burning) and beat in the sifted flour.
Add a ladleful of milk and whisk in. As it thickens, carefully add in another measure of milk, and so on. Add in the mustard and the cheese, and beat together with a wooden spoon until the cheese melts. When the sauce has thickened enough so that it coats the back of a spoon without falling off, take it off the heat.
Preheat the oven to 350ºF [180ºC].
Pour a ladleful of cheese sauce over the entire bottom of a large gratin dish. Then add the first layer of lasagna noodles. (You may need to break some to ensure they fit neatly.)
Over this add a thin layer of tomato sauce. Then a layer of mushrooms, followed by a layer of cheese sauce. Next: a layer of lasagna. (Try to keep the layers as thin as possible.) Repeat until the dish is almost, but not quite, full. Make sure that the topmost layer is lasagna noodles spread with a little cheese sauce.
For the topping, strew over the cheese, then the fried bread crumbs, if using. Bake in the oven for about 35 to 45 minutes.
To make your own fried bread crumbs
Either use prepared fresh bread crumbs or make them yourself. Cut ½ lb [250 g] white bread, remove the crusts, and reduce to crumbs in the food processor, either with the blade or with the grating attachment: this will produce about 1 ¼ cups [100 g] crumbs.
Place 4 Tbsp [50 g] butter in a frying pan and when melted, add the bread crumbs and mix thoroughly. Keep an eye on them as they burn easily. They should take about 15 minutes to turn dark golden.
Slow-Cooked Tomato Sauce
Serves 4 as a pasta sauce
2 Tbsp olive oil
1 large onion, chopped
2 garlic cloves, crushed (optional)
3 x 14.5-oz [400-g] cans tomatoes (my optimal combination is 1 can of whole
tomatoes, 1 of chopped tomatoes and 1 of cherry tomatoes)
1 Tbsp tomato paste
1 tsp sugar
Salt and freshly ground black pepper
Put a nice big saucepan (I prefer wider to higher, as it cooks down more quickly) over medium-high heat, and add the olive oil. When it’s hot, toss in the onion, turn the heat right down, and sweat (i.e., slow-cook in oil) until translucent, pushing it around from time to time. This takes at least 20 minutes. Cook the onion too hot and fast and it will brown and caramelize. You want the onion to be soft and colorless. (You want it nice and soft because once it hits the tomatoes it won’t get any softer.) Add the garlic, if using, 5 minutes before the onion is done. Then pour in the tomatoes and tomato paste, and sugar. Heat it to simmering point (slow bubbling), then turn the heat to medium-low and simmer away, uncovered.
Do keep stirring regularly as the sauce has a nasty habit of sticking; turn down the heat if you think it is boiling too fast. I also use a splatter guard, as it bubbles away like a tub of volcanic gloop, and you may end up with tomato-sauce splodges everywhere. After about 20 minutes, break up any whole tomatoes with the back of a spoon and continue to cook.
After about 45 minutes, add salt and black pepper, to taste. Check the seasoning and add a tiny bit more sugar if you think it needs it. Allow it to cook for a little longer—I reckon it takes a total of 1 hour to reduce properly and become sweet, thick, and unctuous.
Excerpted from Friends Food Family: Essential Recipes, Tips and Secrets for the Modern Hostess, from Liberty London Girl by Sasha Wilkins. Photos by Lisa Linder. Published by Quadrille Publishing, 2015.