Method

• Heat the oven to 400°F (205°C). Set a rack in the center. Drain and rinse the canned lentils, slice the mushrooms, dice the onion and measure both sets of ingredients. Use an oven-safe skillet; keep a 2-quart baking dish available if your skillet cannot go in the oven.
• Heat the oil in the skillet over medium-high heat. Add the mushrooms and cook for 7–9 minutes, stirring occasionally, until their released liquid has mostly evaporated and some edges are browned. Add the onion and cook for 4 minutes. Stir in garlic, thyme and pepper for 30 seconds.
• Sprinkle the 2 tablespoons flour over the vegetables and stir for 1 minute. Gradually stir in the broth, scraping the pan, then add the cream and lentils. Simmer gently for 3–4 minutes until the sauce lightly coats a spoon. Start with 1/4 teaspoon salt, taste and add the rest if needed. Remove from the heat.
• In a bowl, stir the 1 cup flour, baking powder and 1/4 teaspoon salt. Work in the cold butter with a fork or pastry cutter until the mixture resembles coarse crumbs. Stir in cheddar, then milk just until a soft, shaggy dough forms. Do not knead or beat the dough smooth.
• If needed, transfer the hot filling to the baking dish. Divide the biscuit dough into SIX similar spoonfuls and space them over the filling, leaving small gaps. Bake for 18–22 minutes until the filling bubbles around the edges and the biscuits are golden. Split the center biscuit to check that its middle is set with no wet dough; loosely cover browned tops with foil if further baking is needed.
• Let the skillet stand for 5 minutes so the sauce settles slightly. Spoon one biscuit and its surrounding filling onto each plate. Treat the skillet handle as hot even after the pan is on the table.