Blend the almonds and garlic in a food processor until fine. Add the spinach, cheese, herbs, lemon zest and lemon juice to the food processor. Blend the herbs just enough so they are mixed, about 3 seconds. Add the canola oil and olive oil while the food processor is on a low setting. Season with salt and pepper. Blend to desired consistency. Transfer the pesto to a serving bowl. Place the chopped tomatoes on top of the crostini if using and top with pesto. Any leftover pesto should be placed in a bowl and covered with plastic wrap. Press the plastic wrap right on top of the pesto and refrigerate.