Rub chicken with mustard until evenly coated, then slice into chunks to your preferred size. In a frying pan, sear the chicken in olive oil (on a high heat) for about 7 minutes until browning. Remove chicken from pan and set aside.
Turn the heat down to medium and in the same pan cook the garlic and shallot until soft.
Add the mushrooms, broth, thyme, lemon juice, and coconut milk. Continue to cook on medium-high heat until mushrooms begin to soften.
Place the chicken back in the pan with the mushroom sauce and stir well. Simmer for 5-7 minutes on low-medium heat.
Remove from heat, sprinkle with fresh coriander and serve.