Bring a large pot of waterto boil over high heat. Salt it until it tastes like the sea. Add the pasta andcook until al dente (about 7 minutes).
While the pasta is cooking, prep the veggies.
Drain the pasta, reserving one cup of the pasta water
Heat a large, heavy-bottomed skillet over medium-high heat. Add the olive oil, the sundried tomatoes, and the onions. Sauté for 4-5 minutes.
Add the zucchini; season to taste with salt and pepper, and sauté for 3-4 minutes. Be careful not to overcook.
Add the garlic and sauté for another minute.
Add the tomatoes, the pasta, the lemon juice and zest and the pasta water. Season with cracked black pepper and red pepper flakes. Then turn the pasta with tongs (or lift and turn with two spoons) to incorporate everything.
Once everything is nicely together and hot, add the spinach and continue to turn with tongs to incorporate the spinach. When the spinach begins to wilt, turn off the heat and continue turning it until the spinach is well integrated.
Plate and finish with grated parmesan and caper berries.