Preheat and prep: Preheat the oven to 375°F. Slice the baguette into 1-inch pieces and set aside. Thinly slice your onion, cutting with the grain for a soft, caramelized texture.
Caramelize the onions: In a medium saucepan over medium-low heat, melt the butter and olive oil together. Add the sliced onions, a sprinkle of salt, and brown sugar. Cover and let cook for about 15 minutes, allowing the onions to soften. If they start to stick, add 2 tablespoons of water. Remove the lid, add the balsamic vinegar, and cook for another 20 minutes, stirring frequently until the onions reach your desired color and texture. Set aside.
Toast the baguettes: Place the baguette slices on a baking sheet, drizzle with olive oil, and bake for 7–8 minutes, or until lightly golden and crisp.
Cook the Steak-umm: In a clean pan over medium-high heat, drizzle in olive oil and cook the Steak-umm Angus Slices for 2 minutes on each side. Once cooked, slice them into bite-sized pieces and season lightly with salt and pepper.
Build the bites: Spread the garlic and herb cheese onto each toasted baguette slice. Top with shredded Gruyère and bake for 3–5 minutes, until the cheese is melted and bubbly.
Finish and serve: Layer each baguette with sliced Steak-umm and caramelized onions. Drizzle with balsamic glaze and sprinkle with chives. Serve warm and enjoy immediately!