Bring a medium pot of salted water to a boil. Wash and dry produce.

Trim green beans if necessary; cut crosswise into 2-inch-long pieces. Trim scallions; cut whites into 1-inch pieces and thinly slice greens. Peel and mince or grate ginger. 

In a small bowl, combine mayonnaise, half the chili sauce (you'll use the rest later), and as much Sriracha as you like.

Set aside until ready to serve.

Once water is boiling, add noodles to pot. Cook, stirring occasionally, until al dente, 5-7 minutes.

Drain and set aside.

While noodles cook, heat a drizzle of oil in a large, preferably nonstick, pan over medium-high heat. Add beef*, green beans, scallion whites, ginger, and a pinch of salt and pepper. Cook, breaking up meat into pieces, until beef is cooked through and veggies are tender, 4-6 minutes. (For 4 servings, you may need to work in batches.)

Drain any excess grease from pan (or use a paper towel and tongs to sop it up!).

Add soy sauce, remaining chili sauce, and ¼ cup water (½ cup for 4 servings) to pan with beef and green beans; continue to cook, stirring occasionally, until sauce is warmed through, 30-60 seconds.

Remove from heat.

To pan with beef and green beans, add drained noodles and ½ TBSP butter (1 TBSP for 4 servings). Toss to combine; taste and season with salt and pepper if desired.

Divide lo mein between shallow bowls. Drizzle with as much firecracker sauce as you like. Top with scallion greens and serve.