Beef Tenderloin without mayo vegetables

itemscope itemtype="http://data-vocabulary.org/RecipeIngredient"> 2 teaspoons butter, divided 1 cup vertically sliced yellow onion 1 cup vertically sliced red[...]

2 cups beef stock or canned broth, prefer veal stock if possible 1 cup chicken broth or canned low salt broth 4 small carrots peeled, halved lengthwise 16[...]