Slice the seitan into thin, bite-sized strips to ensure maximum surface area for browning.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
Heat the extra virgin olive oil in a large skillet over medium-high heat until shimmering.
Add the seitan strips to the skillet and sear for 4-5 minutes until they are golden brown and crispy on the edges.
Reduce the heat to medium and stir in the minced garlic, rosemary, thyme, sea salt, and black pepper.
Cook for an additional 2 minutes, stirring frequently to prevent the garlic from burning while it infuses the seitan.
While the seitan finishes, toast the sourdough bread slices in a toaster or under a broiler until they are crisp.
In a small bowl, toss the fresh baby spinach with the lemon juice until the leaves are lightly coated.
Place the toasted sourdough on a plate, pile the garlic-herb seitan on top, and finish with the lemony spinach.