Peel potatoes and cut into 1/2-inch cubes. Place potatoes into cold water; cook over medium heat until crisp tender.
Drain tomatoes, reserving juice.
In a heavy saucepan brown butter over medium-high heat. Add green chile strips, garlic, and jalapeno pepper. Cook until most of the moisture has evaporated; drain. Add drained tomatoes; cook 2 minutes more.
Stir flour into tomato mixture. Stir in reserved tomato juice, chicken broth, lime juice, black pepper, salt, white pepper, Worcestershire sauce, and sugar. Cook and stir until thickened and bubbling.
Drain potatoes; add to soup along with cilantro. Simmer 5 to 10 minutes.