Drain tofu and slice into ½-thick square pieces. Stack the squares on top of each other and slice into triangles.
Lay a lint-free towel on a baking sheet. Place the tofu pieces on half of the towel. Fold the other side of the towel over the tofu. Place a second baking sheet on top and stack with cans. Press the tofu for 15 to 30 minutes.
To make the marinade, whisk together the aminos or soy sauce, balsamic vinegar, maple syrup, vegetable oil, sriracha sauce, garlic, and onion in a shallow covered container or resealable plastic bag.
Add the pressed tofu to the container. After one minute flip the pieces over. Cover and refrigerate for 30 minutes, flipping the tofu (or bag) once or twice while it marinades.
When ready to cook the tofu, adjust the rack in your toaster oven to the top or middle position and set to Broil on High. Lightly oil a baking sheet.
Remove the tofu pieces from the container, shake off any excess marinade and place on the prepared pan.
Broil until the top of the tofu is browning and crisped on the edges, about 7 to 8 minutes.
Use oven mitts to remove the pan and carefully flip the tofu.
Return the pan to the toaster oven and broil until the second side is browned about 3 to 6 minutes or more depending on your toaster oven.
Serve warm or at room temperature.
