Heat oil in a large skillet over medium heat. Add garlic and saute for two to three minutes. Add fish, skin side down, to hot skillet. Cook for three minutes. Add a little wine to deglaze and steam, then add onion rings and cover for two minutes. Remove lid, squeeze citrus juices into pan and saute until meat is cooked, about three minutes more.
Transfer trout to serving plates. Remove pan from heat and whisk in butter to thicken sauce. Season with salt and pepper. Place fillet on plate and drizzle sauce over fish. Spoon wild rice pilaf onto plate. Garnish with orange, lemon, or lime slices or wedges.
Notes: Trout is excellent whether pan-fried, grilled, poached, baked, or broiled. Rainbow trout is mildly sweet with a fine, moist texture. It is also easy to bone and has virtually no scales. The wild variety is firmer, darker in color, and better tasting.