French onion soup burgers

Ground beef, beef stock (beef stock, sea salt, honey, cooked vegetables (celery, carrot, onion), caramelized sugar syrup, natural flavor, beef extract, mushroom juice concentrate, tomato powder, spice and herbs (black pepper, bay leaf, thyme), yellow onion, english muffins (unbleached enriched wheat flour (wheat flour, malted barley flour, niacin, iron, thiamin mononitrate, riboflavin, folic acid), water, yeast, contains 2% or less of: sugar, wheat gluten, yeast nutrients (calcium propionate (preservative), citric acid, calcium citrate, vinegar), lemon, baby arugula, gruyere cheese (pasteurized milk, cheese culture, salt, enzymes), unsalted butter (cream, natural flavor), flour (enriched bleached wheat flour (niacin, iron (reduced), thiamin mononitrate, riboflavin, folic acid), malted barley flour), dijon mustard (water, vinegar, mustard seed, salt, white wine, fruit pectin, citric acid, tartaric acid, sugar, spice), thyme.