1. Start by heating a large skillet over medium heat and melt the butter. Add the thinly sliced onions and cook gently, stirring occasionally, until they’re soft and golden brown, about 10-12 minutes. This step fills the kitchen with the kind of aroma that takes me right back to Mama Lou’s kitchen, where the scent of caramelized onions was a daily delight.
2. While the onions cook, warm your beef au jus in a small saucepan. Stir in the Worcestershire sauce, garlic powder, and a pinch of salt and pepper. Keep it warm on low heat.
3. Lay out the tortillas on a clean surface. Evenly distribute the roast beef slices across each tortilla, then sprinkle the cooked onions on top.
4. Generously layer each roll with shredded Swiss cheese. I like to pile it high — Ouma always teased me for being “too cheesy,” but I say, cheese is love!
5. Carefully roll each tortilla tightly from one side to the other, making sure the filling stays tucked inside.
6. Place the roll ups seam-side down on a baking sheet lined with parchment paper. Bake in a preheated oven at 375°F (190°C) for 10-12 minutes, or until the tortillas are slightly crisp and the cheese inside is melted and bubbly.
7. Remove from the oven and let them cool for a few minutes before slicing each roll up in half diagonally. This makes them easier to dip and share, a tradition Ouma and I always look forward to.
8. Serve hot with the warm au jus on the side for dipping. If you like, add a small dollop of horseradish sauce on the side for a little extra punch.

One tip I learned from Mama Lou is to keep the filling well balanced. Too much beef can make rolling tricky, and too much cheese can get messy. Finding that perfect harmony is part of the joy — a little like balancing flavors in any family recipe handed down with love.