Toss sweet potato slices with 1 tablespoon of the olive oil, salt and pepper and spread out onto a baking sheet. Bake for about 1 hour, flipping half way through until crispy on the edges.
Toss the grapes with 1 tablespoon olive oil, salt and pepper and spread out onto another baking sheet. Bake for about 45 minutes, shaking the pan occasionally to roast grapes evenly on all sides.
While sweet potatoes and grapes roast, heat the remaining tablespoon of olive oil in a skillet over medium heat. Add the onion, reduce heat to medium-low and cook for about 25-30 minutes, stirring every 2-3 minutes so that the onions don't burn but slowly caramelize instead. If onions start to dry out towards the end, add a splash of water to the pan. Add the balsamic vinegar during the last 2-3 minutes of cook time to coat onions.
To assemble, place the crumbled jalapeno havarti style cheese on top of each sweet potato round then the caramelized onions on top of that and finish with 1-2 roasted grapes.
Sprinkle with sea salt and garnish with micro-greens before serving. Best served warm but these reheat nicely in a toaster oven as well.