Hubba hubba. Sweet onion goodness. Check it:

Caramelized Onion Tart

Caramelized Onion Tart

Gluten-Free Caramelized Onion Tart

For the Filling

  • 3 large red onions
  • 2 large garlic cloves
  • 2 T olive oil
  • 1 T butter
  • 1/4 c. balsamic vinegar
  • 1/2 tsp. thyme
  • 1/4 tsp. salt (or to taste)
  • freshly ground pepper to taste
  • 1 egg
  • 2 T milk
  • 2 T grated parmesan cheese
  • grated gruyere

For the crust

  • 1/4 c. sorghum flour
  • 1/4 c. teff flour
  • 1/4 c. tapioca flour
  • 1/4 c. + 2 T sweet rice flour
  • 6 T butter, room temp
  • 1/4 tsp salt
  • 1 egg
  • 1 T cider vinegar

Start the onions: Thinly slice the onions and garlic and put in a pan with olive oil and butter. Saute on medium high, stirring occasionally, for 20-30 minutes until onions start to caramelize. Make the crust while you’re waiting for the magic to happen.

Make the crust: Preheat oven to 400 degrees. Put the dry ingredients for the crust into a bowl. Cut the butter into chunks and with your fingertips, smush it into the flour until the butter pieces are pea-sized or smaller and the whole mixture is evenly crumbly. Make a well in the middle and add the egg and vinegar. Scramble gently with a fork to break the yolk and incorporate the vinegar. Slowly incorporate the flour until uniformly wet. Dough will still be lump-crumbly. Get your hands dirty and form into a ball. Roll out between two pieces of wax paper and place in an 8″ tart pan with a removable bottom. Pinch up the sides. Prebake for 10 minutes.

Back to the filling: When onions are uniformly brown and well on their way to caramelizing, add the balsamic vinegar. Add the thyme & salt and pepper to taste. Continue to cook until they have reduced in size to about half what they were raw and have obtained a deep caramel color.

Remove the tart crust from the oven and spread onions evenly over the crust. In a small bowl, beat 1 egg with 2T of milk and 2 T of parmesan or romano cheese. Pour over onions in tart. Top with grated gruyere or another stinky semi-hard cheese. Return to the 400 degree oven and bake for another 20 minutes. Eat. Groan. Good.