Caramelized Onion Tart with seasoning

2 tablespoons olive oil plus extra for brushing phyllo sheets 2 cloves garlic freshly minced 3 each red onions halved and thinly sliced 1 each yellow onion[...]

50 g butter 1 tablespoon olive oil 4 large yellow onions , sliced 1 garlic clove , crushed 2 eggs 2 egg yolks 50 g coarse grain mustard 142 ml double cream[...]