Heat 1 T butter in a saucepan and add onion and garlic. Cook for 3-4 minutes, stirring frequently, until onion is tender. Stir in rice and cook 1 minute more, stirring constantly.
Add wine and cook until evaporated, stirring.
Stir in sweet potato and 1/2 cup of broth. Cook, stirring constantly, until liquid is completely absorbed. Stir in 1/2 cup additional broth. Continue cooking about 20 minutes,stirring constantly and adding 1/2 cup of broth at every time previous additions have been absorbed until rice is creamy and tender. Add the remaining butter and peas and cook until heated, stirring throughout. Remove from heat. Stir in remaining ingredients.