Subway Sweet Onion sauce

Subway Sweet Onion sauce
Ingredients:
1. 250g white sugar
2. 60ml red wine vinegar
3. 60ml white vinegar
4. 1 large sweet onion, grated
5. 15ml sesame oil
6. 15ml Dijon mustard
7. 2.5g mustard powder (or an extra 5ml Dijon mustard)
8. 2.5g onion powder
9. 1.25g garlic powder
10. 1.25g paprika
11. 0.6g celery seed
12. 0.6g poppy seeds
13. Salt and pepper to taste
14. 15g cornstarch
Instructions: