Author: Recipe Courtesy of Margaret M. Johnson, Teatime in Ireland, irishcook.com
Serves: 1 cup
Ingredients
2 tablespoons (1 ounce) unsalted butter
2 tablespoons olive oil
2 large red onions, thinly sliced
¼ cup packed light brown sugar
½ teaspoon fresh thyme
Sea salt, to taste
Ground black pepper, to taste
¾ cup dry red wine
¾ cup malt vinegar
Instructions
In a large saucepan over medium heat, melt butter and oil; add onions and stir until coated. Stir in sugar, thyme, salt, and pepper. Reduce heat to medium-low and cook, stirring occasionally, until onions are soft and caramelized, 25 to 30 minutes.
Stir in wine and vinegar. Continue to cook, stirring occasionally, until mixture is thick and syrupy, 30 to 35 minutes.
Remove from heat and let mixture cool in pan. Serve on sandwiches, or transfer to plastic containers, cover, and refrigerate for up to 2 weeks.
Recipe by TeaTime Magazine at https://teatimemagazine.com/roast-beef-tea-sandwiches-with-red-onion-marmalade/