Step 1: Heat a large skillet over medium-high heat. Add the olive oil and let it heat until shimmering, about 1 minute.
Step 2: Add the frozen green beans directly from the freezer to the hot skillet. Spread them in a single layer. DO NOT stir for the first 60-90 seconds to allow the beans to develop a blistered, crispy exterior.
Step 3: After the initial sizzle, toss the beans and continue cooking for 4-5 minutes, stirring occasionally, until the beans are bright green, tender-crisp, and any excess water has evaporated.
Step 4: In the last 60 seconds of cooking, add the minced garlic, salt, and black pepper. Toss everything together and cook until fragrant, about 30-60 seconds.
Step 5: Remove from heat. If using, stir in the butter until melted. Squeeze fresh lemon juice over the top and serve immediately while hot and crispy!