Impossible Bacon Swiss Pie: Crustless, One Dish, Weekend Easy

A pie with no crust sounds like a contradiction, and that is exactly the trick. Crumbled bacon and diced onion go into the dish, an egg-and-baking-mix batter pours straight over them, and shredded Swiss covers everything. In the oven, the batter settles around the filling and bakes into its own tender bottom layer, so the pie emerges with a crust that never needed rolling, chilling or patching. Cut it into squares and the layers hold perfectly.

Impossible pies earned their name decades ago: pour a simple batter over a filling, bake it, and the batter improbably divides itself into a crusty base, a creamy middle and a browned top. This bacon and Swiss version is one of the most satisfying of the family. The bacon brings salt and smoke, the onion brings sweetness, and the Swiss turns molten over the top while a second layer of it melts into the egg below.

Everything happens in one ceramic dish, there is no pastry anywhere in sight, and the whole thing goes from ordinary pantry ingredients to a puffed, golden pie in about an hour. It suits a weekend brunch as naturally as a no-fuss dinner, and it reheats beautifully the next day.

Ingredients

Why this recipe works

The method works because of how the batter is built. Baking mix already contains flour, leavening and a little fat, so when it is whisked with eggs and milk it forms a thin, pourable batter rather than a dough.

As the pie bakes, that batter separates by density: the heavier flour settles toward the bottom and sets into a tender, crust-like layer, while the egg-rich liquid sets into the creamy middle. The leavening in the mix lifts the whole thing slightly as it bakes, which is why the finished pie comes out puffed and gently domed instead of flat.

The order of assembly matters just as much. Bacon and onion go on the bottom first, so they end up embedded in that settling flour layer rather than floating to the top — the same effect you would get by blind-baking a crust and scattering the filling over it.

The Swiss goes on last, where the dry oven air can toast it into a golden blanket while the cheese closest to the batter melts down into the egg. Heat from all sides, a full 35 to 40 minutes at 350°F, and a patient rest give each layer time to set completely before the knife goes in.

Notes and substitutions

Use regular sliced bacon, not thick-cut; thinner slices render fully and crisp through in the time the skillet allows, and their smaller pieces distribute better through the pie. A white onion is the classic choice here because it stays firm and sweet rather than collapsing.

Whole milk gives the most tender set; the baking mix can be any all-purpose baking mix, or the homemade substitute listed below if the box is empty. Shred the Swiss from a block if you can — pre-shredded cheese carries an anti-caking starch that can make the topping slightly grainy.

The dish in the video is a large rectangular ceramic baker, which is ideal: ceramic heats gently and the rectangle gives tidy, even squares. A 2-quart dish is the right volume; anything much larger spreads the batter thin and shortens the bake, while a deeper dish needs extra time. Keep the dish on a rimmed baking sheet in the oven — the pie bubbles at the edges as it finishes, and the sheet spares the oven floor. Leftover bacon fat can be saved for another use, or simply poured off after cooking the onion.

• baking mix: Whisk together 1 cup all-purpose flour, 1 1/2 tsp baking powder, 1/4 tsp salt and 1 tbsp melted butter; use it in the batter exactly as written.
• whole milk: Half-and-half makes a richer pie; 2% milk works too. Skip nonfat milk, which gives the batter a thinner set.
• Swiss cheese: Gruyère melts beautifully and tastes nuttier; sharp cheddar or Monterey Jack also work in the same amount.
• white onion: A yellow onion or three sliced scallions swap in directly; sweet onions turn milder as they bake.

Equipment

• 2-quart rectangular ceramic baking dish
• large skillet
• medium mixing bowl
• whisk
• cutting board and knife
• thin spatula