Easiest Way to Cook Tasty French Onion Tart
French Onion Tart . You can have French Onion Tart using 17 ingredients and 18 steps. Here is how you cook it. Ingredients of French Onion Tart Prepare 1 tbsp of extra virgin olive oil. Prepare 1 tbsp of butter. You need 2 lb of yellow onions, peeled & sliced thin. Prepare 2 of sprigs fresh thyme - leaves removed & stems discarded. It's 1 of Sea salt and freshly ground pepper, to taste. Prepare 1 large of egg, lightly beaten. It's 1 tsp of sherry vinegar. It's 1 of ½ cup beef, vegetable or mushroom broth. It's 2/3 cup of (2 oz.) Gruyere cheese, shredded. It's 1 of ½ cup cream or half and half. It's of For the cheese pastry crust. Prepare 1 of ¾ cups (110 grams) whole wheat pastry flour. Prepare 1 of ¼ tsp. (2 grams) fine sea salt. It's 1 of ¼ tsp. paprika. Prepare 1 cup of (3 oz.) Gruyere cheese, shredded. Prepare 4 of Tbsps. (2 oz.