Place the peas and 5 cups water in a medium saucepan. Bring to a boil over medium-high heat. Reduce the heat to low and cook, uncovered, for 40 minutes.
Add the garlic to the saucepan. Continue cooking for 5 to 10 minutes longer or until the peas are very soft and falling apart. Cool slightly.
Meanwhile, finely grate 1 and ½ teaspoons lemon zest from the lemon. Juice the lemon, measure 2 tablespoons of juice.
Transfer the peas and garlic to a food processor or high speed blender. Add ½ cup (125 mL) water. Blend until completely smooth.
Add the lemon zest, lemon juice, turmeric, and (optional) salt. Blend until completely smooth, adding more water as needed to achieve a thick, smooth consistency.
Taste and adjust the seasonings to your liking. Transfer to an airtight container and refrigerate until cold (the dip will thicken as it chills).
Serve plain or topped with any of the suggested topping ideas. Use as a dip or spread.
