Spring vegetable pot pie with herb biscuit crust

Chop rosemary, thyme and sage fine.

Mix about half a cup of milk with half a cup of plain yogurt as a buttermilk substitute.

Grate in four tablespoons of cold butter; add 1 tsp baking powder, 1/4 tsp baking soda, a big tablespoon of starch and 1/2 tsp salt, with the herbs.

Stir in flour until the dough just barely seems rollable; keep it wet, almost too sticky, and work it as little as possible. A little less than two cups of flour.

Rest the dough in the fridge to let it hydrate before rolling.

Cut the carrots into rounds.

In a pan tall enough to bake the pie in, melt a big knob of butter; stir in enough flour to make a paste, then the other half stick of butter, for a thick roux.

Stir in white wine a little at a time, then milk, until thick.

Add the carrots and give them a good 10-minute head start.

When the carrots start to soften, add the leek rounds; stir constantly so the thick sauce does not stick and burn.

Season with a big spoon of Dijon mustard and more salt; the sauce should be a little saltier than wanted, since it seasons the vegetables to come.

Shave the kernels off the corn and halve the sugar snap peas; do not pre-cook them.

When the carrots are at least halfway to fork tender, turn off the heat.

Roll out the biscuit dough with lots of flour, or between two sheets of parchment paper, wide enough to cover the pan.

Stir the raw corn and peas into the sauce; it should look too thick, as the vegetables release water as they cook.

Lay the dough over the filling and pinch off the excess; brush with beaten egg and water, or plain water, for shine.

Bake in a 375F (190C) convection oven about half an hour, until the top is brown and the crust does not feel wet or squishy inside.

Cool before cutting so the sauce thickens; ready when the pan can be picked up barehanded. Serve from the pan.