Preheat your oven to 400 degrees.
Heat 2 Tbsp. vegetable oil in a Dutch oven on your stovetop. Dice and add the onion, carrots, celery and garlic and cook for about five minutes, until translucent.
Next, dice and add the potatoes. Cook for 2-3 minutes, then sprinkle in the 1/4 cup flour as you stir. Try to give everything a light coat of flour. Cook for another 1-2 minutes.
Next, slowly add the broth, cream and milk as you stir. Salt and pepper liberally. Then double the amount you just salted and peppered. You think I’m joking, but this takes a LOT of seasoning.
Bring to a simmer and keep simmering for about five minutes, until the mixture has barely thickened. Pull off the heat and stir in the chopped herbs, vinegar and peas.
Next, mix up the biscuit topping (you can actually start this during the five-minute simmer, if you like). Stir together the flour, baking powder and salt. Use a fork to cut in the shortening until the flour forms little crumbs. Use your fingers to mix in the milk as you pour it in slowly – the dough should not be sticky, so go easy. If it is sticky, add a little more flour.
Roll the biscuit dough into a disc roughly the size of your Dutch oven and place it on top. Make sure there is room for the pie to vent either on the sides or by way of vents you can poke with a knife. Place the whole thing in the oven with no lid and bake for 30 minutes, or until the biscuit top is done.