G: Yes, using the oven broiler is the best choice for London broil if you want to avoid grill marks. Here’s how to get a great result without the seared lines:

🔥 Why the Broiler Works:

It mimics a grill with high direct heat from above.
You get caramelization and browning, but no grill grates, so no marks.
Broiling also keeps the meat’s juices near the surface for a tender result.

✅ Basic Broiler Method (No Grill Marks):

Preheat your broiler for at least 5 minutes. Use the top rack, about 4–6 inches from the heat.
Pat the London broil dry, then season or marinate as desired.
Place on a broiler-safe pan or foil-lined baking sheet, ideally on a flat rack (optional).
Broil each side 5–7 minutes, depending on thickness and desired doneness.
- Flip once halfway through.
- Use a meat thermometer: aim for 130°F for medium-rare, 140°F for medium.
Rest 5–10 minutes before slicing thinly against the grain.

🔧 Optional Tips:

Use a cast iron pan under the broiler if you want more crust.
Avoid sugary marinades if you’re using high heat—they burn easily.
Crack the oven door slightly if your model allows, to prevent smoke buildup.

Let me know if you want a marinade or spice rub suggestion tailored to their tastes.

M: For this marinade: I have no wine. Suggestions? 4 large cloves garlic, chopped

3 sprigs rosemary, leaves roughly chopped (about 1 tablespoon)

1/2 cup balsamic vinegar

1/2 cup red wine

1/2 cup extra-virgin olive oil

Freshly ground black pepper

1 2-inch-thick piece beef top round for London broil (about 3 pounds)

Kosher salt

G: Here are three solid options to replace the ½ cup red wine in your marinade, depending on what you have on hand and the flavor profile you want:

🔁 Direct Substitutes (No Wine):

1. Beef Broth + Balsamic Boost (Savory, balanced)

Replace ½ cup red wine with:
- ¼ cup beef broth
- ¼ cup additional balsamic vinegar
Adds depth and keeps acidity strong.

2. Pomegranate or Grape Juice + Vinegar (Fruity like wine)

Replace ½ cup red wine with:
- ⅓ cup pomegranate or grape juice
- 2 tbsp balsamic or red wine vinegar
Mimics the fruity acidity of wine.

3. Water + Worcestershire Sauce + Lemon Juice (Savory, punchy)

Replace ½ cup red wine with:
- ⅓ cup water
- 1 tbsp Worcestershire sauce
- 1 tbsp lemon juice or vinegar
Good umami substitute with no sweetness.

All three options keep the garlic, rosemary, and balsamic at center stage while replacing the wine’s acidity and depth. The broth option is safest if you're unsure of their taste preferences.