01 -
Heat the oven to 425°F, toss cherry tomatoes with about one tablespoon of the measured oil and some salt and pepper, then roast about 15–20 minutes until blistered.
02 -
Pat cod dry, coat with the remaining oil while reserving a little for garlic if omitting butter, and season lightly.
03 -
Heat a clean grill or grill pan over medium-high heat and cook the fillets carefully, allowing about 3–4 minutes per side as a starting point and verifying 145°F at each thick center.
04 -
Gently warm garlic in the optional butter or reserved oil, stir in cream and simmer briefly; lower the heat and add dill, lemon and seasoning.
05 -
Spoon sauce onto plates, add tomatoes and fish, and serve immediately without leaving the cod in the hot pan.