Hot Sauce

My poor brother, a man who likes flavorful foods, has recently been diagnosed with some food sensitivities that cause severe gastric distress (use your imagination).

One of these sensitivities is to fructan (?), which is apparently in both garlic and onion. Both fresh and dry/powdered.

Unfortunately, most of his favorite sauces contain garlic. "Simpler" sauces like Tabasco are fine, but he wants to also find some sauces that are more complex than pepper and vinegar.

So, what can this community suggest for your favorite sauces without garlic or onion in them?

Thanks!