Cut steak crosswise into 1/4-inch-thick strips. Toss together with garlic, and 2 tablespoons lime juice; marinate the steak for 15 minutes. Heat 1/2 teaspoon olive oil in a wok or nonstick skillet over medium-high heat. Cook the steak with the marinade, stirring constantly, for 2-3 minutes or until medium-rare; transfer with slotted spoon to a large bowl, and set aside. Add bell peppers and onion to the wok; cook, stirring, for about 7 minutes or until just tender. Transfer the pepper-and-onion mixture to a bowl with the steak. Add 1/2 teaspoon olive oil and asparagus to wok; cook, stirring, for about 4 minutes or until tender. Put the pepper-onion-and-steak mixture back into the wok. Add ginger, soy sauce, sesame oil, and 1 tablespoon lime juice to wok; cook, stirring, for about 2 minutes or until heated through. Add cooked brown rice to the wok; heat for 2 minutes. Divide the stir-fry among 4 plates, and distribute chopped cilantro and chopped cashews evenly on top; serve.