Preheat the oven to 400F and line two baking sheets with parchment paper.
Thinly slice yellow onions.
Heat a small pot over medium-high, add 2 tbsp of olive oil. Add the yellow onion slices, stirring every 2 – 3 minutes.
After 5 – 10 minutes, once the heat is strong and the onions start to brown, turn the heat to medium-low. Stir every 2 – 3 minutes, allowing the onions to evenly caramelize. This should take about 20 minutes.
Transfer onions to a small bowl and cool in the refrigerator.
In a small bowl, combine almond milk and lemon juice. Set aside.
As that sits, prepare grated cheese and finely chopped thyme.
In a large bowl, combine the all-purpose flour, salt, sugar, baking powder, and chopped thyme. Whisk ingredients together.
Remove the caramelized onion from the fridge and add the bouillon paste or seasoning, coating evenly.
Cut the cold butter or vegan butter into small cubes and add to the large mixing bowl. Using a pastry cutter or hand mixer, incorporate the butter, breaking it into smaller pieces until it resembles the size of green peas or just larger.
To the same bowl, add the almond milk and lemon juice mixture.
Fold in by hand or with a wooden spoon until half mixed In addition, add the caramelized onion. The dough should come together easily. If it is too dry, add a small amount of milk if needed. Be sure not to overmix.
Remove the dough from the bowl onto a gently floured surface. Lightly roll the dough out to about 1 ½- 2 inches thick. Using a 2 ½ or 3 -inch round cookie cutter, cut out the biscuits, placing them directly onto the baking sheets evenly spaced apart. They will expand as they bake.
Prior to baking, place a large amount of grated vegan cheese or grated gruyere cheese on top of each biscuit.
Bake biscuits for 14-16 minutes, until golden brown on the bottom. Remove from oven and let them rest until cooled.
Notes
If you're not vegan, replace vegan butter with equal parts regular butter. You can use your preferred plant-based milk instead of almond milk OR use buttermilk (which you can omit the lemon juice).Replace vegan cheese with desired cheese, gruyere, or remove altogether. Swap thyme for your favorite fresh herbs. They are interchangeable!Serve biscuits with butter or plant-based butter.Store biscuits at room temperature in an airtight container for 2 days OR in the freezer for 1 month.