Name: Cajun Catfish with Sweet Onion Relish
Ingredients: 4 U.S. Farm-Raised Catfish fillets; 2 teaspoons olive oil, divided; 1 cup chopped sweet onion (i.e. Vidalia); 1 cup chopped, seeded Roma tomatoes; 3 tablespoons pitted and chopped calamata (Greek) olives; 2 tablespoons water; 1 tablespoon dried thyme leaves, divided; 1 tablespoon paprika; 1/2 teaspoon garlic salt; 1/8 teaspoon ground red pepper (cayenne), or more to taste

Why it works: Onion and garlic match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 29,058 recipes. Both carry furaneol, which smells caramel, strawberry. The science ↓

Explore the science

The flavor team

The pairs that carry this dish. Each one is judged two ways: how much their aromas overlap, and how often cooks already put them together.

Onion + garlictop 1% of all pairs

Smell alikestrong

Cooked together29,058 recipes

Shared aroma: furaneol (caramel, strawberry).
Olive + tomatotop 1% of all pairs

Smell alikemoderate

Cooked together15,539 recipes

Shared aroma: 3-hexenal (apple, fruity).
Olive + garlictop 2% of all pairs

Smell alikemoderate

Cooked together25,665 recipes

Shared aroma: linalool (floral, citrus).
Tomato + garlictop 3% of all pairs

Smell alikemoderate

Cooked together14,076 recipes

Shared aroma: furaneol (caramel, strawberry).
Thyme + peppertop 4% of all pairs

Smell alikemoderate

Cooked together11,585 recipes

Shared aroma: beta-phellandrene (minty, terpene).

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

What each ingredient does

Catfish fillets: Provide the main protein, which turns opaque and flakes when cooked through.
Sweet onion: Sautéing softens its sharpness and adds natural sweetness to the relish.
Roma tomatoes: Add moisture and fresh acidity to the relish.
Calamata olives: Add salty, briny richness that balances the sweet onion and tomatoes.
Paprika: Adds color and mild smoky-sweet aroma to the spice rub.

The step that matters

Grill 5 minutes on each side. Fish is done as soon as it flakes easily; overcooking dries the delicate flesh, so check with a fork rather than relying only on the timer.

Swap the onion

How well each one fits the dish's main ingredients (catfish, olive, tomato, thyme, garlic, pepper):

Capsicumfits better
Okrafits better
Eggplantfits about as well
Onionthe original

Fit is the average pairing score against catfish, olive, tomato, thyme, garlic, pepper. Candidates are from the same food group and used in at least 100 recipes.

“What each ingredient does” and “The step that matters” were written by Claude from this recipe’s own method and reviewed in samples by CompKitchen.

Ingredient	Portion assumed	kcal
Olive Oil	1 tbsp (14g)	119
Onion	1 medium (110g)	44
Tomato	1 medium (123g)	22
Chili	1 tsp (2.7g)	8
Cayenne	1 tsp (1.8g)	6
Olive	1 large (4g)	4
Thyme	1 tsp dried (1.4g)	4
Salt	1 tsp (6g)	0
Catfish	not in our table	0
Water	not in our table	0

Cajun Catfish with Sweet Onion Relish