Sauce: Heat a good glug of oil in a small saucepan on medium-high heat. In a medium bowl add garlic,cherry tomatoes, shallots, olives, and salt and pepper to taste. Put your mixture into the saucepan and cook, stirring occasionally, until tomatoes start to break down. Add white wine, bring to a boil, then reduce heat to simmer while you cook the fillets. Squeeze in lemon juice to taste.