Combine shallot, chile, garlic, vinegar, and 1 tsp. salt in a medium bowl. Let sit 10 minutes. Stir in cilantro, parsley, and oregano. Using a fork, whisk in oil. Transfer ½ cup chimichurri to a small bowl; season with salt and reserve as sauce.
If using for beef, place meat in a glass, stainless-steel, or ceramic dish. Toss with remaining chimichurri. Cover and chill at least 3 hours or up to overnight.
Remove meat from marinade, pat dry, and grill.
Spoon reserved chimichurri over grilled meat.