another good recipe: http://www.seriouseats.com/recipes/2011/02/homemade-ketchup-from-scratch-recipe.html
You might need to buy:
- red wine or apple cider vinegar
- packed brown sugar
- salt
- dried red chili flakes
You might need to buy:
- grape-seed oil or peanut oil
- extra-virgin olive oil
- white wine vinegar
- lemon juice
- Dijon mustard
- large egg yolk