Preheat Oven to 400F. Prepare the biscuits first. Combine the flour, baking powder, soda and salt in the bowl of a food processor. Pulse in the cold butter until the size if small peas. Add the buttermilk while pulsing until a cohesive dough forms. Turn out the dough, roll until 1/2" thick and cut into twelve rounds. Put the biscuits in the freezer.
Prepare the stew. Heat the olive oil in a Dutch oven (or use a pot and transfer to a casserole dish). Sauté the onions until translucent, about five minutes. Add the carrots and leaks. Cook until soft. Add the dill, thyme, lemon zest, chicken stock and Navy beans. Bring to a simmer. While you're waiting, create a slurry with the corn starch and half and half.
Pour in the slurry, and turn the heat to medium low. Allow to simmer on low until thickened, about ten minutes. It may look curdled at first, but it will even out as it thickens.
Remove the pot from the heat and arrange the biscuits so the stew is evenly covered. There might be some gaps. Bake at 400 for 14-18 minutes, until the biscuits have crispy golden tops and the stew is bubbly. Let rest for five minutes before serving..
Dedicated locavore. I spend my weekends on the back roads (often lost!) looking for the best ingredients Ohio has to offer. I am often accompanied by my husband, Mr. Radar and our dog, Buddy. Born in West Virginia, raised in Michigan, I moved to Ohio for college and have lived there on and off since. I love to meet farmers and local producers. Cooking is an extension of this love.
You can follow my move from government analyst to cottage industrialist and view the food I cook for my personal mad scientist on thistleconfections.com