With a fork, pierce the sweet potato in several places. Place the sweet potato in the microwave, on top of a piece of paper towel, and cook for 3 minutes per side (about 6 minutes total), or until the sweet potato is tender when pierced with a fork.
Let the sweet potato cool for several minutes, or until cool enough to handle. Cut in half lengthwise.
Carefully scoop out the flesh of the potato and place in a medium-sized bowl. Reserve the skins.
With the back of a fork, mash the potato flesh until most lumps are gone.
Add the coriander, paprika and salt, and mix to combine.
In a small bowl, whisk together the tahini, lemon juice and agave nectar. Toss with the arugula.
Toast the bread, then divide the sweet potato mixture between the two pieces of toast. Top with the dressed arugula. Serve.