Place large cast iron skillet or frying pan over medium-low heat. Add rolled oats and almonds and toast, stirring frequently, until lightly toasted and fragrant, about 2 minutes. Remove to bowl and replace pan back over medium-low heat.

Add coconut oil and maple syrup to pan and cook until bubbly, about 30 seconds to 1 minute. Stir in reserved toasted oats and almonds, chia seeds, hempseeds, flaxseed, cinnamon, and salt. Cook mixture, stirring often with heatproof spatula or wooden spoon, until mixture turns golden brown and fragrant, about 3 minutes. Remove pan from heat and set aside, allowing granola to cool at room temperature for at least 20 minutes. If you push granola into a pile in center of pan and let it cool, it will form granola clusters. Granola will become crunchy as it cools. Granola can be stored in airtight container for up to 1 week.

When ready to assemble salad, using sharp knife, cut a small slice from bottom and top of each grapefruit. Place one cut side on cutting board and, working from top down, cut peel off, making sure not to leave a lot of white pith on the outside. Cut each grapefruit in half, then slice into half-moons about 1/2 inch thick. Discard any seeds and place in large bowl along with jicama, avocado, and olive oil. Gently toss together and divide among 3 serving bowls. Top with sprinkle of fresh mint, ground black pepper, and 2 Tbsp granola on each salad.