Soy and fish sauce are both good flavour enhancers for steak. Combined they add a distinctive flavour similar to that of dry-aged beef. Plenty of sodium in both, so there’s no need for salt unless you like a lot. Then use salt when you blast the steaks.
That raw garlic you like can get mixed with the butter too. Whiz the garlic and butter, and a little white wine if you’re allowed some carbs. Plus some freshly ground black pepper and some minced parsley from the pot on your windowsill and you have the Maitre d’Hotel Butter posh steakhouses serve on top of steaks. Switch up the wine for something more distinctive if you like. Maybe a touch of Bourbon?