Inspired by Food for My Family
4 8-ounce beef tenderloin steaks
4 tablespoons butter, divided
1 large shallot, diced
2/3 cup dry red wine
1/3 cup balsamic vinegar (good quality)
2 tablespoons rosemary, minced
Kosher salt and freshly ground black pepper
Remove steaks from refrigerator 30 minutes before cooking. Season well with salt and pepper. Melt 2 tablespoons butter in large saute pan over medium high heat. Add fillets and sear on each side for 4 minutes, remove to platter.
Add remaining 2 tablespoons butter and shallots. Saute a few minutes till shallots are tender. Add the wine and vinegar to deglaze, then add rosemary. Reduce sauce by half and add 1/2 teaspoon salt if needed.
Return steaks to pan, and cook to desired doneness, flipping once during cooking time. Serve over mashed potatoes if desired with sauce.