Brush the onion slices with a little olive oil and season with kosher salt and pepper. On a hot griddle pan or in a cast-iron skillet, grill until tender and slightly char-marked.
In a food processor, combine the grilled onion, sun-dried tomatoes, garlic, shallots, basil, and cumin. Pulse into a chunky puree. With the motor running, slowly drizzle in the olive oil, then the lemon juice. The mixture should be quite smooth.
Transfer to a large bowl and add the Chickpea confit. Fold together to blend. Return to the food processor in batches, and purée until the mixture is smooth and thick. Season to taste with pepper and salt (if the sun-dried tomatoes are very salty, you may not need much). The texture is a matter of taste; if it is very thick, add a little more olive oil to yield a creamier result. Well covered, the spread will last for at least a week in the refrigerator.
For two different textures, puree half the spread until very smooth and pale, and leave the other half chunky.
If you refrigerate the spread overnight, you can return it to a nice creamy texture by rewhipping in the food processor (pulse on and off for 1 minute).
The Wedge: Cut a small triangle of pita and smear with Chickpea Spread. Top with a pinch of crumbled feta and some sliced scallions, picked sprigs of parsley or dill, and a few slivers of olive.