Beetroot, feta and walnut tarts | Women's Weekly Food

Ingredients

• Onion Jam
• 2 onions, thinly sliced
• 2 tablespoons brown sugar
• 1/2 tablespoon mustard seeds
• 1/4 cup water
• 1/4 cup balsamic vinegar
• 1/4 teaspoon salt
• 1 sheet of frozen puff pastry, defrosted and cut into quarters
• 450 grams can of sliced beetroot, drained and diced
• 75 grams feta
• 1/4 cup walnuts, chopped
• 1 tablespoon rosemary sprigs
• 1/2 tablespoon olive oil