Strawberries don't exactly come cheap, so it's especially disappointing to bite into a seemingly juicy specimen only to discover that it's firm, underripe, and practically flavorless. Thankfully, not all is lost. There are two ways these blah berries can be rescued.
Macerate the Berries
Halve, quarter, or slice the berries (depending on their size and your preference) and add them to a mason jar or reusable plastic container. Gently toss the berries with a sprinkling of sugar — about two teaspoons per pint is a good place to start, though less-sweet berries might need more. For extra flavor, add freshly squeezed lemon or lime juice (about one teaspoon per pint), and if you're feeling wild, one teaspoon of kirsch per pint. Cover, and refrigerate for at least an hour, or until the berries have gotten juicy, softened slightly, and taste sweeter.
Roast the Berries
Preheat your oven to 350°F. Halve, quarter, or slice the berries (depending on their size and your preference) and arrange them in a single layer on a parchment-lined rimmed sheet pan. (If your strawberries are particularly bland, toss them with one teaspoon of sugar first.) Roast until tender and the flavor has intensified, about 20 minutes if you sliced the berries; around 40 if you halved or quartered them.