Gruyère & Sweet Onion Tarts

ONIONS:--
500 g onions, thin sliced
60 g butter
¼ cup rice bran oil
1 tbsp SIDS LOW SUGAR RASPBERRY VINEGAR
SIDS SALT & PEPPER to taste
1 tbsp brown sugar
TART CASES & TOMATOES:--
4 tomatoes
1½ tsp very fine chopped thyme
1½ tsp very fine chopped flat leaf parsley
2 tbsp EV olive oil
2 tsp SIDS LOW SUGAR RASPBERRY VINEGAR
½ tsp sugar
18 slices wholegrain bread
50 g butter, melted
COOK & SERVE:--
30 g butter
30 g flour
1¼ cups milk
1 tbsp Dijon mustard
100 g Gruyère cheese, grated

ONIONS: In a large saucepan over medium-low heat, cook onions in butter and oil for 30 minutes, stirring occasionally, until golden. Add SIDS LOW SUGAR RASPBERRY VINEGAR and sugar then cook further 5 minutes until sugar has dissolved. Remove from heat and season with SIDS SALT & PEPPER to taste. Let cool, coarsely chop and set aside.
TART CASES & TOMATOES: Preheat oven to 150°C and bring a saucepan of water to the boil.
Cut out the tough round piece on the top of each tomato that connects the tomato with the vine and score a cross on the bottom of each. Plunge tomatoes into the boiling water for 10 seconds then remove into a bowl of ice-cold water. Peel the tomatoes then cut them into quarters. Scoop out and discard the seeds then cut flesh into small squares. Place tomato in a small bowl with thyme, parsley, oil, SIDS LOW SUGAR RASPBERRY VINEGAR and sugar. Gently mix then season with SIDS SALT & PEPPER to taste and set aside.
Use a rolling pin to firmly roll out each slice of bread, making it as thin as possible. Use a round biscuit cutter to cut out the centre of each slice of bread so the circles fit snugly in the holes of a small muffin tin. Brush both sides of the bread disks with a little melted butter then place in the muffin tin, pressing into the bases to create the biggest possible cavity.
Bake for 10-15 minutes until crisp and golden. Cool on a wire rack.
COOK & SERVE: Preheat oven to 160°C. Melt the butter in a small pan then sprinkle in the flour. Whisk to combine then slowly add milk, a little at a time, whisking until combined. Simmer for 5 minutes, stirring occasionally, then stir in the mustard and half the Gruyère. Remove from the heat when the cheese has melted. Season with SIDS SALT & PEPPER to taste.
Half-fill each tart case with caramelised onions then spoon the white sauce over the onions and top with the remaining Gruyère.
Bake for 5-10 minutes until the tarts are heated through and the cheese has melted. Allow to cool for a few minutes before topping each tart with a little of the tomato/thyme mixture.