Preheat oven to 180°C (360°F).
Roast the potatoes
Toss chopped potatoes with olive oil and a pinch of salt. Spread in a casserole dish and roast uncovered for 20–30 minutes, until softened enough to pierce easily with a fork but not fully cooked.
Make the kale pesto
While the potatoes cook, blend kale, basil, pecans, lemon juice, garlic, olive oil, and salt in a food processor or high-speed blender until smooth. Set aside.
Add tomatoes
Remove potatoes from the oven and increase heat to 200°C (400°F). Stir and flip the potatoes with a spatula. Arrange tomatoes over the potatoes, then sprinkle with sliced garlic and a little more salt.
Finish baking
Return the dish to the oven and bake for 30 minutes, until tomatoes begin to caramelize and release their juices. About halfway through cooking, gently press the tomatoes to help release their juices.
Optional crisp finish
For a crispier top, place under the broiler/grill for a few minutes until lightly browned.
Serve
Spoon kale pesto over the warm bake just before serving or serve alongside.