Cube the watermelon into 1-inch pieces and hull the strawberries, then spread both in a single layer on a parchment-lined baking sheet. Freeze at 0°F for at least 4 hours or overnight until completely solid, with a clearly firm, frozen surface.

Transfer the frozen watermelon and strawberries into a high-powered blender or food processor. Blend on high, stopping to scrape down the sides as needed, until the mixture is completely smooth and creamy for about 60–90 seconds, with no visible ice chunks.

Add honey (or agave), fresh lime juice, lime zest, and a pinch of sea salt to the blender. Blend again briefly until fully incorporated, then taste and adjust sweetness or lime so it tastes slightly bolder than the final sorbet.

For a soft-serve consistency, scoop immediately into chilled bowls or glasses. Serve right away for a creamy texture that holds shape on the spoon.

For a firmer sorbet, transfer to a freezer-safe container, smooth the top, and freeze for 1–2 hours until scoopable. Before serving, let sit at room temperature for 3–5 minutes to soften slightly, then scoop and garnish with fresh mint, a squeeze of lime, and optional flaky sea salt.