Chop the trimmed rhubarb stalks into small pieces

Place rhubarb, 1/2 cup sugar, and 1/4 cup water in a large saucepan.

Cook over medium heat until rhubarb has broken down to a pulp.

Stir occasionally and squish out any lumps with a wooden spoon.

Remove from heat. Let cool completely.

Zest and juice the lime.

In a separate small saucepan, combine the lime zest, lime juice, thyme leaves, and 1/4 cup each of sugar and water.

Cook over low heat until the sugar dissolves.

Remove from heat and let cool completely.

Combine the rhubarb pulp with the lime thyme syrup.

Chill for 1 hour.

Process the mixture in an ice cream maker according to the manufacturer's directions.

Transfer to a container and chill for 5 hours or overnight.

Scoop and serve.