01 - Combine the rinsed quinoa and water (or broth) in a saucepan. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes or until liquid is absorbed. Remove from heat, fluff with a fork, and set aside to cool.
02 - Preheat a grill or grill pan to medium-high heat. Lightly brush pineapple rings with olive oil. Grill for 2–3 minutes per side until distinct char marks appear and the fruit is caramelized. Remove, let cool slightly, and cut into bite-sized chunks.
03 - While the grains and fruit cool, dice the red bell pepper, chop the red onion, slice the chilies, halve the tomatoes, and chop the cilantro.
04 - In a large mixing bowl, combine the cooled quinoa, grilled pineapple chunks, red bell pepper, red onion, chilies, cherry tomatoes, and cilantro. Add the avocado if using.
05 - In a small bowl, whisk together the olive oil, lime juice, maple syrup (or agave), ground cumin, salt, and black pepper until emulsified.
06 - Pour the dressing over the salad mixture and toss gently to coat all ingredients evenly. Taste and adjust seasonings if necessary. Serve chilled or at room temperature.