1 Put Chicken Thighs In A Medium Sized Saucepan And Just Cover With Water. Add One Clove Of Garlic That Has Been Cut In Half, 1/4 Of An Onion, And 1 Teaspoon Of Salt To The Water. Bring To A Boil, Reduce To A Low Simmer, And Cook, Covered, For 20 Minutes, Until The Chicken Is Just Cooked Through. Remove Chicken Thighs To A Separate Bowl And Let Cool Enough To Touch. 2 While The Chicken Is Cooking, Put The Tomatillos And 3 Serrano Chile Peppers In A Separate Sauce Pan And Cover Them With Water. Bring To A Boil, Reduce To A Simmer. Simmer Until The Tomatillos Are Cooked, And Have Changed Color, But Are Not Mushy, About 5 Minutes. Remove From Heat. Use A Slotted Spoon To Transfer Tomatillos And Serranos To A Blender. Add 1/2 Cup Of The Tomatillo Cooking Liquid To The Blender, As Well As 2 Cloves Of Garlic, A Third A Cup Of Your Chopped Onion, And About 1/4 Cup Of Chopped Cilantro (Packed). (Remaining Chopped Onion And Cilantro Will Be Used For Garnish.) Add One Teaspoon Of Salt. Pur