My uncle brought these to our first spring patio party and you will not believe this elegant appetizer only takes 4 ingredients to throw together.

My uncle first carried a tray of these oven baked 4-ingredient beef and brie crostini out to our patio one chilly early-spring evening, right when the snowbanks were finally giving up. We were all wrapped in light jackets, watching the fields slowly turn from brown to green, and here he came with this simple but elegant appetizer that looked like something from a little city bistro. No fancy list of ingredients, no fussy prep—just a crusty baguette, good roast beef, creamy brie, and a swipe of prepared horseradish for a bit of Midwestern zip. They’re perfect when you want something that feels special but still fits into a busy day of getting the yard and garden ready for the season.

Serve these crostini warm right from the oven on a simple platter or even straight off the foil-lined baking sheet for a casual patio feel. They pair nicely with a light red wine, a crisp hard cider, or a cold beer. I like to round things out with a big green salad, a bowl of pickles, and maybe a plate of raw vegetables with ranch dip. For a spring gathering, set them alongside a pot of soup or a simple pasta salad and you’ve got an easy spread that lets you enjoy your guests instead of hovering over the stove.

Servings: 8–10 as an appetizer

1 crusty baguette (about 12–14 inches)

Preheat your oven to 400°F (200°C). Line a large baking sheet with aluminum foil for easy cleanup.

Slice the baguette into 1/2-inch thick rounds. You should end up with roughly 20–24 slices, depending on the length of your loaf.

Arrange the baguette slices in a single layer on the foil-lined baking sheet so they are close together but not overlapping.

Spread a thin smear of prepared creamy horseradish sauce on each slice of bread. Go lightly at first—you can always add more next time if you like more heat.

Cut the brie into small slices that will fit nicely on the baguette rounds. Place a piece of brie on top of the horseradish on each slice. It’s fine if the rind is on; it softens and adds flavor.

Tear or fold the shaved roast beef into small, nest-like piles and place a bit on top of the brie on each slice. Don’t pack it too tightly; a loose fold lets the beef warm through nicely.

Place the baking sheet on the middle rack of the preheated oven and bake for 8–10 minutes, or until the bread edges are toasty, the brie is melted and gooey, and the roast beef is warmed through.

If you’d like a little extra color on top, switch the oven to broil for 1–2 minutes, watching closely so the bread doesn’t burn.

Remove the baking sheet from the oven and let the crostini sit for 2–3 minutes so the cheese can settle slightly. Transfer to a serving platter or serve directly from the foil-lined sheet for a relaxed patio party feel. Enjoy while warm.

You can easily adjust these crostini to suit your crowd while keeping the spirit of the original four-ingredient idea. If you prefer a milder flavor, choose a double-cream brie and use less horseradish, or pick a mild prepared horseradish sauce instead of a hotter version. For a bit of sweetness, you can swap the horseradish for a thin layer of fig jam or apricot preserves (still keeping it to four ingredients total by making only one spread choice). If you like extra crunch, lightly toast the baguette slices alone in the oven for 3–4 minutes before topping and baking. To stretch the recipe for a larger group, use a longer baguette and slightly thinner slices of brie and roast beef so you can make more pieces without losing the balance of flavors. Food safety tips: Keep the roast beef refrigerated until you’re ready to assemble, and don’t leave the finished crostini sitting out at room temperature for more than 2 hours. If you are preparing ahead, you can slice the bread and cheese and keep them covered in the refrigerator, but wait to add the horseradish and roast beef until just before baking so the bread doesn’t get soggy and the meat stays at a safe temperature. Always wash your hands and any cutting boards or knives that touch the deli meat before using them for other ingredients.