Heat oil in large deep skillet - add onion and saute for 2 minutes. Add mushrooms and 2 Tbsp coconut amino, cook 1-2 minutes. Then add lentils, broth, thyme, salt and pepper, bring to boil then reduce to simmer and cook for 20 minutes.
Mix cornstarch and water (start with 1 tsp and if still needs thickening add additional 1 tsp cornstarch with water), add to lentils and stir until thickened about 1 minutes. Add additional coconut amino if desired for flavor.
Serve over mashed potatoes, mashed cauliflower, or baked potatoes.