Step 1

Inspect 2 pint jars for cracks and rings for rust, discarding any defective ones. Immerse in simmering water until jam is ready. Wash new, unused lids and rings in warm soapy water.

Step 2

Combine tomatoes, sugar, basil, onion, lemon juice, vinegar, salt, pepper, coriander, and cumin in a medium saucepan over medium heat. Bring to a boil, stirring occasionally.

Step 3

Reduce heat to low and simmer, stirring occasionally, until thickened and reduced by half, 2 to 3 hours. Remove from heat.

Step 4

Divide jam between jars. Allow to cool slightly before covering with lids. Refrigerate jam for up to 2 weeks or freeze for up to 4 months.