Beef Tenderloin With Sauteed Mushrooms with shallots

4 tablespoons butter 2 tablespoons olive oil 14 ounces white button mushrooms , sliced (can use more) 2 -3 tablespoons shallots , finely chopped (or to taste)[...]

2 tablespoons olive oil , divided 5 cloves garlic , peeled and minced 1 onion , finely chopped 10 ounces fresh mushrooms , sliced 1 lb baby spinach, washed[...]

4 beef tenderloin steaks , cut 1 inch thick (about 6 oz. each) 1/2 cup uncooked lentils 1/2 cup water 2 cups ready-to-serve beef broth , divided 1 teaspoon[...]