Prime Rib Steak Sub

The Prime Rib Steak Sub is a special sandwich with tender, slow-cooked prime rib steak slices, sweet caramelized onions, melted provolone cheese, fresh lettuce, tomato, deli mustard, and homemade garlic mayo, all served on a toasted sub roll.

Prices & Calories

Small – $6.99 (419 cal)

Medium – $9.99 (810 cal)

Large – 13.99 (1340 cal)

Choose Your Bread

• White Bread: $0.00
• Wheat Bread: $0.00

Choose Extra Toppings

• Banana Peppers: $0.00
• Black Olives: $0.00
• Black Pepper: $0.00
• Red Wine Vinegar: $0.00
• Salt: $0.00
• Pickles: $0.00
• Jalapeño: $0.00
• Oil: $0.00

Other Side Options

• Double Meat: $1.25
• Crispy Bacon: $0.00
• Sautéed Mushrooms: $0.50
• Extra Provolone Cheese: $0.25

Remove Options

• Skip the Dressing: $0.00
• Skip the Pickles: $0.00
• Skip the Provolone Cheese: $0.00
• Skip the Mayonnaise: $0.00
• Skip the Barbecue Sauce: $0.00

Prime Rib Steak Sub Calories

• Small: 419 kcal
• Medium: 810 kcal
• Large: 1340 kcal

Prime Rib Steak Sub Nutrition

Small Sub 

Nutrient	Amount
Calories	400 kcal
Calories from Fat	180 kcal
Total Fat	20g
Saturated Fat	7g
Trans Fat	0g
Cholesterol	50mg
Sodium	1050mg
Total Carbohydrates	30g
Dietary Fiber	2g
Sugars	4g
Protein	25g
Vitamin A	8% DV
Vitamin C	4% DV
Calcium	10% DV
Iron	12% DV

Medium Sub 

Nutrient	Amount
Calories	800 kcal
Calories from Fat	360 kcal
Total Fat	40g
Saturated Fat	14g
Trans Fat	0g
Cholesterol	100mg
Sodium	2100mg
Total Carbohydrates	60g
Dietary Fiber	4g
Sugars	6g
Protein	50g
Vitamin A	12% DV
Vitamin C	6% DV
Calcium	18% DV
Iron	25% DV

Large Sub

Nutrient	Amount
Calories	1300 kcal
Calories from Fat	580 kcal
Total Fat	65g
Saturated Fat	20g
Trans Fat	0g
Cholesterol	170mg
Sodium	4000mg
Total Carbohydrates	90g
Dietary Fiber	5g
Sugars	10g
Protein	75g
Vitamin A	18% DV
Vitamin C	8% DV
Calcium	24% DV
Iron	35% DV

Prime Rib Steak Sub Allergens

Allergens	Are They Present?
Egg	Yes
Gluten	Yes
Milk	Yes
Nitrates	Yes
Seeds	Yes
Wheat	Yes
Fish	No
MSG	No
Peanuts	No
Shellfish	No
Soy	No
Sulfites	No
Tree Nuts	No

Firehouse Subs Prime Rib Steak Sub (Copycat Recipe)

The Prime Rib Steak Sub from Firehouse Subs is legendary—a hearty, limited-time favorite stacked with tender prime rib, caramelized onions, provolone cheese, and bold sauces. While their exact recipe is a trade secret, this copycat brings the same rich flavors home with a few key steps: slow-cooked beef, golden onions, and a garlic mayo spread that ties it all together.

Ingredients

For the Prime Rib Steak

• 1–1.5 lbs prime rib roast (or ribeye/top sirloin)
• 1 tbsp olive oil
• Salt and black pepper, to taste

For the Caramelized Onions

• 1 large yellow or white onion, thinly sliced
• 1 tbsp olive oil or butter
• Pinch of salt and pepper

For the Garlic Mayo

• 1/2 cup mayonnaise
• 1–2 cloves garlic, minced or grated
• 1 tsp lemon juice (optional, for brightness)

For the Sandwich

• 1 large sub roll or baguette
• 4–6 slices provolone cheese
• Deli mustard (to taste)
• Shredded iceberg lettuce
• Sliced tomato
• Dill pickle spear (for serving)

Instructions

1. Cook the Prime Rib (Reverse Sear Method)
   • Preheat oven to 250°F (120°C).
   • Season roast generously with salt and pepper. Place on a wire rack over a baking sheet.
   • Roast until internal temperature reaches your desired doneness (about 125°F/52°C for medium-rare).
   • Rest 15 minutes, then sear in a hot skillet with olive oil for 1–2 minutes per side until browned.
   • Thinly slice against the grain.
2. Caramelize the Onions
   • Heat olive oil or butter in a skillet over medium-low.
   • Add sliced onions and a pinch of salt. Cook slowly for 20–30 minutes, stirring occasionally, until golden and sweet.
3. Make Garlic Mayo
   • Mix mayonnaise, garlic, and lemon juice (if using). Chill until ready to use.
4. Assemble the Sub
   • Slice and lightly toast the sub roll.
   • Place provolone slices on one half and broil briefly until melted.
   • On the other half, spread deli mustard and garlic mayo.
   • Layer with caramelized onions, sliced prime rib, lettuce, and tomato.
5. Finish & Serve
   • Close the sandwich, slice in half, and serve warm with a dill pickle spear.

🔥 Pro Tips for the Best Copycat

• Wrap the finished sub in foil for a few minutes to mimic Firehouse’s steamed effect.
• Add extra provolone for a cheesier bite.
• Use leftover prime rib from a roast dinner—this sub makes it shine.

Prime Rib Steak Sub – Review

FAQs

Keep in mind: The details provided are from publicly accessible sources and might not be entirely precise. For the most accurate nutritional information, it’s recommended to visit the firehousesubs website or reach out to them directly.

The price can vary based on your location. It’s best to check the specific price through the firehousesubs website or app for delivery to your area.