Simmer the pineapple juice with the salt in a saucepan over medium heat for about 10 minutes. Then stir in the espresso and agave syrup, simmer for another 15 minutes.
If you don`t want your sauce to be vegan, you can just use honey instead of agave syrup.
After a while, the liquid will take on a syrup-like consistency. So it`s perfect.
Now add the pesto and tomato ketchup and stir everything together. The pesto should be a red one with sundried tomatoes. Now just take the pot off the stove and let it cool down.
The quantities given apply to a fairly normal aroma. If you want it salty, you should use more salt or stir in a little more of the pesto. If you want it fruity, you should take more pineapple juice. But I recommend following the quantities given here.