Place yellow mustard, mustard, honey, cinnamon and salt in a glass or stainless steel vessel and cover with vinegar to come up about 1/2" above the mixture.
Squeeze lemons for juice (1/4 cup). Place in large sauté pan: onions, 1 cup broth, tomato paste, mustard, lemon juice, vinegar, Worcestershire, salt, and pepper; stir until combined. Bring to a boil ...