In a medium bowl, toss the chard with the shallots, lemon juice, and 1 tablespoon of the olive oil. Stuff the trout cavities and close with skewers. (My skewers were a bit too large, so you could probably use some thick toothpicks to do this also). Season the outside of the fish with salt and pepper and sprinkle with cornmeal.
In a large skillet, heat 1/8 inch of olive oil under medium high heat. Add the trout and cook until skin is crisp and fish is cooked, about 8 to 10 minutes, depending on the size of your trout. Transfer trout to a plate and wipe your skillet clean.
Melt the butter in the skillet and add the trout back in. Turn to coat well. Remove from the heat and allow trout to sit in butter for about 5 minutes or so. This adds so much flavor to the fish, it's definitely not a step to skip.
While you're waiting for the trout, you can make your squash and corn. In a medium skillet, add 1 tablespoon of olive oil and heat under medium high heat. Add squash and corn and saute until squash starts to soften, about 5 minutes.
Serve trout with the squash & corn mixture and with lemon wedges!