Heat 1 tablespoon olive oil in a medium saucepan over medium heat.  Add peas, spinach and mint and sauté until spinach wilts, about 2 minutes.  Remove to bowl of food processor and pulse briefly until coarsely chopped.

In same saucepan, heat remaining olive oil over medium heat.  Add garlic and onion and sauté until onion becomes translucent, about 1 minute.  Add rice and stir to coat grains.  Add wine and stir until absorbed.  Add chicken stock and bring to a boil; cover and reduce heat to low.  Simmer 20 minutes. 

Remove from heat and stir in mint mixture and mascarpone cheese.  Season with salt and pepper, if desired.

For Chicken:

While rice is cooking combine 5-spice powder and teriyaki sauce in a small bowl.  Brush chicken with mixture.  Discard remaining sauce.  Heat grill pan over high heat.  Reduce heat to medium and coat pan with a little olive oil.  Grill chicken until cooked through.  Serve with minted rice.