Biscuits and Gravy

For the gravy:

In a 4-qt saucepan, heat the butter over medium. Add the onion, garlic, celery, and carrots and cook, stirring until carmelized, 15 minutes. Add the mushrooms and flour and cook, stirring until the flour is absorbed into the vegetables, 2 minutes. Add the milk in a steady stream, half a cup at a time, stirring constantly and allowing the mixture to warm each time before adding more milk. Add the salt, pepper, paprika, and sour cream, stir to incorporate then whisk in the cornstarch slurry. Cook until thickened, 2 to 3 minutes, then remove from heat.

For the biscuits:

Preheat the oven to 350 degrees F. Unto a large mixing bowl, sift the flour, baking powder, baking soda, salt, and pepper. Gently stir in the milk, butter, cheese, and scallion until the dough just comes togehter. Turn the dough onto a floured work surface, gently shape it into a 1-in-thick circle, and cut out 12 biscuits using a 2 1/2 in cookie cutter, gently gathering and re-rolling excess dough. Arrange on a baking sheet and bake for 10 minutes, then rotate the pan and bake until just slightly browned, 10 to 11 more minutes. Keep warm.