Mornay onion tart
In a shortcrust pastry base, a rather thick onion tart, where onions and lardons are deliciously bound with a Mornay sauce.
21 K 5.0/5 (27 reviews)
2 hours 15 min.
Easy
6 people
7 IngredientsLast modified on: June 23th 2024
For 6 people, you will need:
- 1
300 g shortcrust pastry (pâte brisée) - 2
1 kg onion - 3
50 g butter - 4
150 g smoked pork belly (or thick cut streaky bacon) - 5
4 tablespoons vinegar - 6
300 g mornay sauce - 7
30 g grated cheese - Total weight: 1,890 grams
Change measures:
Times for this recipe
Preparation: 1 hour 3 min.
Cooking: 1 hour 15 min.
All in all: 2 hours 15 min.
If you start now, at , you will finish around : ?.Change start time
To finish around 7pm, you'll need to have started before: .Change end time
Step by step recipe
Stage 1 - 20 min.
Roll out 300 g shortcrust pastry (pâte brisée) then line a 22 cm (9-inch) diameter high-sided baking tin, which you will have placed on a sheet of baking paper in a baking tray.
Leave any excess dough around the edges, then place in the fridge to set aside.
Leave any excess dough around the edges, then place in the fridge to set aside.
Stage 2 - 10 min.
Stage 3 - 3 min.
In a large saucepan over medium heat, melt 50 g butter, and when hot, add the onions.
Season with salt and stir well.
Cover for the first 5 minutes.
Season with salt and stir well.
Cover for the first 5 minutes.
Stage 4 - 10 min.
Leave to cook until the onions are tender, checking the salt seasoning as cooked onions tend to be a little sweet.
Stage 5 - 5 min.
Your onions should be fairly dry, with little or no cooking juices.
If this isn't the case, because they've given off a lot of water during cooking, drain them in a fine sieve.
Set aside.
If this isn't the case, because they've given off a lot of water during cooking, drain them in a fine sieve.
Set aside.
Stage 6 - 3 min.
Preheat oven to 200°C (390°F).
Cut 150 g smoked pork belly (or thick cut streaky bacon) into small pieces.
Cut 150 g smoked pork belly (or thick cut streaky bacon) into small pieces.
Stage 7 - 8 min.
Toast them, without adding fat, in a small frying pan over medium heat.
Stage 8 - 1 min.
When toasted to your liking, add 4 tablespoons vinegar, and stir until evaporated.
Stage 9 - 2 min.
It's not essential, but I recommend adding 2 or 3 spoonfuls of already-cooked onions to the pan at the end of cooking, then stirring well to capture all the flavor of the grilled bacon.
Stage 10 - 2 min.
Pour the lardons + onions into the remaining onions and mix well.
Stage 11 - 2 min.
Add 300 g mornay sauce and mix well.
Stage 12 - 20 min.
Take the pastry mould out of the fridge, cut the excess pastry around the edges of the mould, place a sheet of baking paper on the bottom and fill with ceramic balls (or similar).
Bake at 200°C (390°F) for 20 minutes.
Bake at 200°C (390°F) for 20 minutes.
Stage 13 - 5 min.
In the meantime, you can roll out the pastry scraps into small strips to decorate the tart.
Stage 14 - 1 min.
After 20 minutes, remove the baking tray from the oven...
Stage 15 - 5 min.
... and remove paper and beads.
Stage 16 - 2 min.
Fill the tart with the onion-lardon-Mornay mixture.
Stage 17 - 2 min.
If you have made some, place the pastry strips on top.
Stage 18 - 3 min.
Sprinkle with a little grated cheese.
Stage 19 - 30 min.
Bake for a further 30 minutes.
Stage 20
Enjoy warm or hot, on its own or with a small green salad.
Remarks
If you find your onions a little too soft at the end of cooking, you can add a good glass of dry white wine.
If you don't have a Mornay sauce, use a Béchamel sauce to which you can add grated cheese to taste.
You'll notice that in this recipe, the onions are cooked without coloring, but if you prefer, you can caramelize them. In this case, increase the weight of onions to 1.5 kg, as they will reduce even more.
If you don't have a Mornay sauce, use a Béchamel sauce to which you can add grated cheese to taste.
You'll notice that in this recipe, the onions are cooked without coloring, but if you prefer, you can caramelize them. In this case, increase the weight of onions to 1.5 kg, as they will reduce even more.
Keeping: 1 or 2 days in the fridge, protected by cling film.
Source: Home made.
Nutritional information
| Proteins (gr) | Carbohydrates (gr) | Fats (gr) | Energy value (in k-calories) | Energy value (in k-joules) | |
|---|---|---|---|---|---|
| Whole recipe | 360 RDI=140 % | 1,490 RDI=140 % | 1,280 RDI=200 % | 3,420 RDI=170 % | 14,320 RDI: 170 % |
| Per 100 g | 20 RDI=7 % | 80 RDI=7 % | 70 RDI=10 % | 180 RDI=9 % | 760 RDI: 9 % |
| Per person | 60 RDI=20 % | 250 RDI=20 % | 210 RDI=30 % | 570 RDI=30 % | 2,390 RDI: 30 % |
How much will it cost?
- For 6 people : £4.65
- Per person : £0.80
Change currency: 
Note: Be careful, these prices are only an estimate, you can consult the table of prices by ingredients used for this estimate.
This recipe uses (among others)
Onion
Like these other recipes: Polenta parmentier, Chicken with rice and leeks, Roscoff loaf, Vegetable stock, Spaghetti with mussels and basil, ... See them all 147
Shortcrust pastry (pâte brisée)
You can get more informations, or check-out other recipes which use it, for example: Quiche Lorraine, French custard tart, Mexican tart, Potato and cheese pie, Gisèle's Pasties, ... See them all 16
Mornay Sauce
You can get more informations, or check-out other recipes which use it, for example: Manou's zucchinis garnished, Eggs Florentine, Spinach Mornay, Small green vegetables in Mornay sauce, ... See them all 4
Smoked pork belly (or thick cut streaky bacon)
Like these other recipes: Dandelion salad, Boeuf (beef) bourguignon, Express sauerkraut, Warm lentil salad, Soup Cornouaillaise, ... See them all 6
Other recipes you may also like
Apple and pear tart
Apples and pears are combined in this sophisticated autumn tart. The pears are laid decoratively on top of stewed apple.October 27th 2014102 K 24.9 60 min.
Green bean purée
Green (or French) beans are usually served whole, for instance as an accompanying vegetable or in a salad, but they make a good purée, too. This is tasty on its own, but also goes very well with meats, and children usually prefer it to "normal" beans.August 11th 202391 K 25 min.
Chestnut cake
This delightful cake is doubly chestnutty: it contains chestnut flour, and sweet chestnut purée.May 8th 2020343 K5 1 hour 15 min.
Bouquet garni
Used very frequently in French cuisine, a secret of French chefs, it adds flavour to a lot of recipes, and it's easy to prepare. The basic principle is to make a small bundle of herbs, bind them in green leek leaves and to tie it up, so that the whole thing can be removed and discarded easily after...March 21th 2017425 K3.5 15 min.
How to cook Morteau sausage well
This is, in my opinion, the best smoked sausage. You can cook it in a number of ways, here are three of the best known.November 15th 20182.77 M 23.4 40 min.
News list of cooking-ez.com
Sign up to receive the latest recipes (next batch due to be sent on 2025-08-24)
Note: We'll never share your e-mail address with anyone else.
Post a comment or question
Follow this recipe
If you are interested in this recipe, you can "follow" it, by entering your email address here. You will then receive a notification immediately each time the recipe is modified or a new comment is added. Please note that you will need to confirm this following.
Note: We'll never share your e-mail address with anyone else.
Alternatively: you can subscribe to the mailing list of cooling-ez.com , you will receive a e-mail for each new recipe published on the site.