In a large bowl, combine the steak pieces, mushrooms, garlic, soy sauce, olive oil, basil, thyme, salt and pepper. Cover and set in the fridge for 15 to 30 minutes.
Then, take the bowl from the fridge and set it on the counter for 15 minutes.
Cut out 4 large heavy-duty foil sheets. If you don't have heavy-duty foil, you can just double up on regular foil.
Divide the steak and mushrooms between the sheets of foil. Wrap the foils tightly around the steak and mushrooms and seal them together.
Grill Method
Preheat the grill to HIGH.
Transfer the foil packets to the grill and grill over high heat for 8 to 10 minutes per side, adjusting the time based on your preferred steak doneness. Use an Instant Read Meat Thermometer to poke through the foils and check on the steak's temperature.
Remove from the grill and let stand for a couple of minutes. Carefully open up the foils, garnish with crushed red pepper flakes and green onions, then serve.
Oven Method
Preheat the oven to 425˚F.
Wrap foils tightly around the steak and mushrooms and seal it all together.
Cook for 18 to 20 minutes or until the internal temperature of the steak reaches about 130˚F to 140˚F. Use an Instant Read Thermometer to check for doneness. Just poke through the foil with the thermometer and set it into one of the steak pieces.
If you want a nice char on the steak, open up the packets the last 2 minutes of cooking and pop them under the broiler for a minute.
Garnish with crushed red pepper and green onions, then serve.
Notes
Marinating Time: Longer marination can enhance flavor and meat tenderness.
Consistent Sizing: Cut the steak cubes uniformly for even cooking.
Aluminum Foil: Opt for heavy-duty foil to prevent tears and leaks.
Space: Leave a small space inside foil packets for better heat circulation.
Check For Doneness: Use an instant-read thermometer for precise steak doneness.
Mind the Grill: Watch for flare-ups if grilling, adjusting heat or packet placement if necessary.
Rest Before Serving: Let packets sit for a few minutes after cooking to redistribute the juices.
Add Variety: Add vegetables, like bell peppers or zucchini, to the packets.
Storage: Store any leftovers in the fridge for up to 3 days.
Serving Suggestion: Serve with rice, pasta, or a salad.
Avoid Overstuffing: Don't overload the foil packets.