20ouncesgluten free Irish stoutI used Steadfast oatmeal cream stout
2tablespoonsapple cider vinegar
1 1/2tablespoonsstone ground mustard
2bay leaves
salt and pepper to taste
For the topping
4slicesUdi's rye breadcut into cubes
1tablespoonbutter
leavesfrom 2 sprigs of thyme
3/4cupgrated white Irish cheddar
Instructions
Place 2 tablespoons of butter in a large Dutch oven or heavy bottomed pot over medium-low heat.
Once melted, add onions and brown sugar. Stir to combine and cook until deep golden brown and caramelized, about 45 minutes - 1 hour. Stir occasionally while cooking and add beef broth as needed to keep from burning (I used about 1/2 a cup during the caramelization process).
When onions are done, add garlic, thyme and remaining 1 tablespoon of butter to the pot. Cook for 1-2 minutes until fragrant.
Add flour, stir to coat all the onions and cook 2 more minutes.
Add the stout, remaining 3 cups of beef broth, apple cider vinegar, mustard, bay leaves, salt and pepper. Stir and bring to a boil. Once boiling, lower to a simmer and cook/reduce for 30 minutes.
Season to taste with salt and pepper and turn off heat.
Preheat oven to high-broil.
Make the topping by placing the butter and thyme in a medium skillet over medium heat.
Once melted, add the bread cubes and toast in skillet until golden brown on all sides.
Ladle soup into oven safe bowls/crocks, top with the toasted croutons and divide the cheese evenly over the croutons in each bowl.
Place bowls on a baking sheet and broil for 3-5 minutes until cheese is melted and bubbly.