Dice yellow new potatoes, about 1 1/2 cups worth. Dice onion.
Heat butter in a large sauce pan over medium heat. Add potatoes, onions and garlic, cook until onion is translucent, about 5 minutes.
Stir in the all-purpose flour, curry, garam masala; saute for 30 seconds, stirring constantly.
Add the broth and milk. Bring to a boil, reduce heat to low, cover, and simmer for 15 minutes, or until potatoes are tender, stirring occasionally.
Stir in the peas and cook, uncovered, for 5 minutes.
Season with lime juice and salt to taste.
Garnish each serving with yogurt and cilantro.