Recipe from Make It Paleo II
halved and seeded
finely diced yellow onion
unsalted grass-fed butter
ghee or lard
plus 2 teaspoons balsamic vinegar
plus 1 teaspoon granulated maple sugar
juice of 1 lemon
grinds black pepper
pinch of red pepper flakes
Place the tomatoes in a food processor and process into small chunks.
In a saucepan over medium-low heat, caramelize the onion in the butter until light brown, about 20 minutes.
Add the tomatoes and the remaining ingredients and simmer for 1 1/2–2 hours, stirring periodically, until the jam has reduced by about half and is thick, like a very thick tomato sauce.
It will keep for 2–3 weeks in the refrigerator.
Find more easy gluten-free, paleo recipes here: https://cookeatpaleo.com/recipes