Wash chicken thighs and pat dry with paper towels. Arrange chicken pieces in the crockpot.
In a small bowl, mix together ginger, water, sesame oil, fish sauce, sriracha sauce, peanut butter, crushed red pepper, coconut milk, tomato paste, salt and pepper. Whisk mixture until well combined.
Pour sauce over chicken and using a spoon, toss the chicken around, making sure each piece is fully coated and covered with the sauce.
Cook on low for 5 to 6 hours or on high for 4 hours. Stir in chopped cilantro.