Using a food processor or mini-chopper, add all ingredients except for lime juice; pulse until well combined.
Transfer 1 Tbsp of Paste into a small bowl and mix with the lime juice; set this mixture aside. (Note: it will be used after grilling.)
For the Steak
Using a fork, poke steak every ~2”. Place steak in glass or porcelain baking dish. Spread Paste evenly on both sides of steak and then sprinkle with salt and pepper. Cover dish and let rest at room temperature for 30-60 minutes.
Preheat grill to medium heat. Brush grates with canola or vegetable oil.
Grill for 8-10 minutes over medium-high heat, flipping after 4 minutes. (Note: Feel free to adjust grilling time to match personal preferences for doneness of steak. 8-10 minutes should yield a fairly well-done flank steak.)
Remove steak from grill; let rest for 5 minutes before slicing.
Cut steak against the grain into ¼” slices. Place slices in large bowl; add reserved Paste and toss until well coated.
For the Tacos
Place several slices of steak on each tortilla. Top with corn, onion, cilantro and sour cream. Serve with lime wedges.