Found this recipe years ago never made them because my son is not a fan of onions...decided to finally make it and to my surprise he took one of these cups and ate it with no complaints! If I didnt see it with my own eyes I wouldn't have believed it. Rest of family loved them too.
Preheat oven to 400. Invert a muffin pan and lightly grease4 the back side of ten muffin cups w/olive oil. Pat a biscuit flat and place over greased muffin cup and stretch dough to cover cup. Repeat w/remaining biscuits. Bake until golden brown about 7 minutes....let cool slightly then remove biscuit cups carefully fom pan and invert onto a baking sheet to cool completely.
Meanwhile heat a medium cast-iron skillet over med-high heat. Add 2 tblsp. of olive oil and the onions, 1/4 tsp.salt n 1/4 tsp.blk.pepper cook stirring every 3 min. for 15 min. or until onions are softened n are browned. Divide onion mixture among the biscuit cups.
In a small saucepan melt butter over med-low heat. Whisk in flour until smooth. Pouring slowly whisk in heavy cream (or 1/2 n 1/2) and cook, stirring until thickened. Stir in mustard. Remove from heat and stir in 1/2 of the cheese. Season w/ salt n pepper. Spoon the cheese sauce over the onions, sprinkle w/the thyme and remaining cheese. Bake until cheese is melted and biscuit edges are golden ...5 minutes and ENJOY!