Mahnke Family Recipes- Herb-Crusted Beef with Onions

Ingredients

• 1 t / 7 g olive oil
• 3 large onions, yellow, chopped
• 1 t / 6 g table salt, divided
• 1 lb / 454 g lean tenderloin beef, trimmed of visible fat
• 1 t Dijon mustard
• 1 ⁄ 2 t dried rosemary
• 1 ⁄ 2 t dried thyme
• 1 T parsley, fresh, finely chopped
• 2 t balsamic vinegar
• 4 c / 130 g kale, cooked