In a large skillet, heat the oil over medium-low heat and cook the onion, stirring, until limp and starting to brown, 4 to 5 minutes.
Add the Maggi and stir to blend.
Add the yams and broth.
Bring to a boil, then reduce the heat to medium-low, cover and simmer until the yams are almost tender, 8 to 10 minutes.
Add the cream, chipotle sauce, salt, and pepper.
Cook uncovered, stirring, until the sauce reduces and thickens and the yams are very tender.