• Preheat a grill to high heat or 450°F if grilling. If using a skillet, preheat the skillet over medium-high heat.
• Season the sirloin steaks with kosher salt on both sides.
• Grill top sirloin or cook on skillet until med-rare or desired temperature. Time will depend on size of cut. Remove from heat and rest for at least 3 minutes. May tent with foil while cooking other ingredients

Grill the bread

• Slice a baguette into 1/2 inch slices. Drizzle olive oil over bread. Grill on hot surface until lightly browned or grill marks develop. Remove from heat and set aside

Saute the mushrooms and shallot

• In skillet over medium high heat, add butter and olive oil. Add sliced mushrooms and continue to cook until water evaporates and mushrooms are lightly browned. Add shallot. Cook until shallot is translucent.
• Season with pepper and salt to taste if needed. Hold warm until appetizer assembly.

Make the Cheese Sauce

• Make a roux. In small saucepan over medium heat, combine butter and flour. Continue stirring and cook for 1 minute being careful not to brown.
• Make the bechamel: Whisk in warm milk and continue to whisk to avoid lumps. When sauce thickens, lower the heat.
• Add desired cheese gradually, melting between additions. Add fresh ground pepper, salt to taste. May add pinch of fresh ground nutmeg or cayenne if desired.
• May thin cheese sauce if needed with additional milk.

Assemble the Steak Bites

• Place grilled baguette slices on platter, top with mushroom mixture, thinly sliced top sirloin, cheese sauce and scallion.
• Serve immediately.